xeriscape design concepts for large lots solutions to the challenges of landscaping on the west...

Toni Boot and Janelle Parchomchuk

December 2009

Xeriscape Design Concepts Xeriscape Design Concepts Xeriscape Design Concepts Xeriscape Design Concepts

for Large Lots for Large Lots for Large Lots for Large Lots Solutions to the Challenges of Solutions to the Challenges of Solutions to the Challenges of Solutions to the Challenges of

Landscaping on the West BenchLandscaping on the West BenchLandscaping on the West BenchLandscaping on the West Bench

About This PublicationAbout This PublicationAbout This PublicationAbout This Publication This manual is a publication based on the Large Lot Xeriscape Design Workshop held

on November 14, 2009 for the West Bench Irrigation District. It closely follows the outline

of the Workshop (see Table of Contents, facing page), while keeping within the scope of the

Large Lot Xeriscape Design Project Terms of Reference.

It is written and presented specifically for the residents who live:

(1) on the large lots of the West Bench area of Penticton, BC and

(2) use water purveyed by the West Bench Irrigation District.

However, anyone wishing to explore xeriscaping will find the manual beneficial,

particularly if large lot sizes or highly erodible or silty soils are a concern on their property.

Soil conditions similar to those of the West Bench occur in various locations within the

Regional District of the Okanagan-Similkameen, the City of Penticton, and the District of

Summerland. They are also known to exist in other parts of the BC Interior such as

Kamloops, Princeton and Prince George.

Xeriscape Design Concepts for Large Lots: Solutions to the Challenges of Landscaping on the

West Bench is not simply a “How to Xeriscape” manual. It also includes information on how

to manage and reduce the risks of hazardous soil erosion on the West Bench.

To get the full benefit of the colour in this publication, it is best to download and save

it on your computer. If you choose to print the document, use a colour printer and

8.5” x 11” paper (Letter size). To reduce paper use, print on both sides, if possible.

This icon represents a particular design consideration or implementation

process that can result in considerable cost-saving when converting a large, West

Bench, landscaped lot to xeriscape.

This icon represents information or ideas that are particularly helpful to owners of

large West Bench properties.

This icon represents a method to reduce erosion of West Bench soils.

This icon represents a special Tip or Idea.

Cover Photo:

Native Plant Bed, Grasslands Nursery

Table of ContentsTable of ContentsTable of ContentsTable of Contents Introduction ............................................................................................................................................ 4

Xeriscape on the West Bench ................................................................................................................. 5

1 Planning and Design................................................................................................................ 6

Planning Considerations, The Base Plan......................................................................... 6

Design Considerations ..................................................................................................... 7

Tips for Low-Maintenance Design ................................................................................... 7

2 Soil Analysis and Amendment ................................................................................................ 8

Soil Variability, Amending the Soil ................................................................................. 8

3 Practical Turf Areas................................................................................................................ 10

Conserving Resources on Your Turf Area..................................................................... 10

How to Remove Turf ...................................................................................................... 11

4 Plant Selection ....................................................................................................................... 15

Grouping Plants by Water and Sun Requirements....................................................... 15

“Spread the Word — Not the Weed” ............................................................................. 16

5 Efficient Irrigation ................................................................................................................. 17

Irrigation Design, Zones ................................................................................................. 17

When to Water ............................................................................................................... 18

Watering Frequency........................................................................................................ 18

Soil Penetration .............................................................................................................. 18

Watering New Plantings ................................................................................................. 18

Irrigation Systems............................................................................................................ 21

Automatic Timers and Monitoring Weather ................................................................ 24

System Maintenance and Water Audits......................................................................... 24

6 Mulch ..................................................................................................................................... 25

Benefits of Organic Mulch ............................................................................................. 26

Using Rock Mulch .......................................................................................................... 26

Costs and Coverage ........................................................................................................ 26

Mulching Tips ................................................................................................................. 26

7 Maintenance........................................................................................................................... 27

Managing Run-off from Roofs and Driveways ..................................................................................... 28

Steps to Harvesting Rainwater................................................................................................... 28

Tips ............................................................................................................................................. 29

Driveway and Roof Runoff........................................................................................................ 29

Landscape Features to Capture, Distribute and Infiltrate Water............................................. 30

Plant List for the West Bench.......................................................................................................... 31-35

Locally Invasive or Potentially-Invasive Species.................................................................................... 35

Resources ............................................................................................................................................... 36

Bibliography ......................................................................................................................................... 38

Index .................................................................................................................................................... 39

IntroductionIntroductionIntroductionIntroduction The hazardous soil conditions of the West Bench area of Penticton have been detailed

in numerous studies since the 1960’s. The most notable of these was done in 1992 by

Klohn Leonoff: West Bench/Sage Mesa Area Geological Hazards Review. The report advises that

high groundwater loads from settlement have contributed to and continue to create the

potential for hazardous subsurface erosion due to the high silt content of the soils. This takes

the form of slumping bluffs as well as subsurface piping and can lead to a number of deleteri-

ous effects, including damage to homes, roads and other utilities.

The majority of the recommendations from the 1992 Klohn Leonoff report have been

implemented on the West Bench and environs at the regulatory level, and are aimed at

reducing groundwater loading including:

• a moratorium on additional septic systems through prohibiting further

subdivision of land in the area

• monitoring leakage of pools and water systems.

In addition to reducing slumping and erosion of the high silt content lacustrine soils on

the West Bench, implementing xeriscape has a number of other positive effects

including:

• mitigation of climate change impacts on water supply

• reduced water use by residents in anticipation of water metering

• efforts to realize cost savings through reduced power consumption

• reducing the rate of deterioration on water supply infrastructure and associated cost

savings.

The West Bench Irrigation District Board felt a timely opportunity existed to address

another recommendation of the report, specifically:

“Dry land landscaping is beneficial, particularly for residents living near the edge

of bluffs. Irrigation water added for lawns and gardening can be detrimental to

geologic stability.

A process of educating all residents of the potential hazards and their associated

risks, along with methods of mitigating these problems, could go a long way to

reduce the occurrence of subsurface erosion caused by development.”

The Large Lot Xeriscape Design Workshop, held November 14, 2009, was the first step

toward education. The Workshop was attended by a cross-section of West Bench residents,

and industry and government representatives. This Manual, Xeriscape Design Concepts for

Large Lots: Solutions to the Challenges of Landscaping on the West Bench, is a compilation of the

information, discussion, and findings of the full-day Workshop.

Xeriscape on the West BenchXeriscape on the West BenchXeriscape on the West BenchXeriscape on the West Bench

The West Bench Irrigation District has identified several factors that make large lot

xeriscaping a strong option to consider in the West Bench area:

• reduced water use minimizes the hazards associated with the erosion of silty soils

• water conservation helps to mitigate the effects of climate change and development

pressures

• the lessened water demand will save costly upgrades to the pump house and pipe-

lines resulting in the reduction of water bills

• xeriscape reduces the power and water costs which will become evident when water

meters are installed in the next 2-5 years.

The word ‘xeriscape’ ('zir-ə-skāp, 'zer-ə-skāp) originates from the Greek word xeros, mean-

ing “dry”. Definitions abound for the term but they all have one thing in common: conserv-

ing water in the landscape.

There are many reasons to xeriscape:

• water use can be reduced by more than 50%

• reduction of erosion hazards on sensitive soils

• lower water use = lower maintenance

• eliminates use of toxic pesticides and herbicides

• a tangible, enjoyable way to reduce your impact on

our environment

• low-water native selections provide food and habi-

tat for South Okanagan birds, butterflies and bees

• a xeriscape will survive restricted water use during

drought conditions.

Xeriscape follows seven established principles. Gener-

ally, each principle builds on the one previous to it; strive to

achieve the full benefits of xeriscape by implementing all

seven steps:

1111 Planning and Design 5555 Irrigation

2222 Soil Analysis and Amendments 6666 Mulch

3333 Practical Turf Areas 7777 Maintenance

4444 Plant Selection

�Dryland landscap-

ing is beneficial,

particularly for resi-

dents living near the

edge of bluffs.

Irrigation water

added for lawns and

gardening can be

detrimental to

geologic stability.”

1992 Klohn

Leonoff Report

Planning and DesignPlanning and DesignPlanning and DesignPlanning and Design

Eighty percent of the 351 rural resident lots occurring in the West Bench are .5

to .75 acres; the remaining 20% are larger. For this reason, a good plan and xeriscape design

is especially critical to West Bench residents. The finished design:

• can save a lot of time and money

• makes it easier to budget and complete the project over several years

• allows you to accurately compare estimates from landscape contractors

• makes you really think about how you use your landscape…and how you could use it

• will make your xeriscape materialize in an organized manner.

Do your own planning, then have a landscape designer review your final plan.

If your project runs two years or more, plant the trees and large shrubs first. You’ll

want to enjoy the benefits of trees (for example, cooling effect, reduced greenhouse

gases) as soon as possible. And, it’s much easier and less costly to move perennials

and small shrubs should the need arise!

Planning Considerations Here are a few things to think about when planning your xeriscape:

• Site — sun/shade; wind exposure; slopes; rocky areas; drainage; moisture; traffic

noise, etc. It is particularly important on the West Bench to recognize the silty soils

because of their erosion hazard, low permeability, and low organic content. Also

consider the site’s proximity to bluff edges, gullies and sinkholes.

• Use — youngsters; out-of-doors entertaining; vegetable garden; pets; sports;

outbuildings; water catchment and dispersal, etc.

• View — from inside the house or from a deck; screening.

• Microclimates — sun path; cold troughs; windy areas; dry or moist shade.

• Grade — always ensure the ground slopes away from your house.

The Base Plan After measuring the site, including elevations, draw a base plan to scale. Include:

• residence, outbuildings, patios, telephone poles, lot boundaries, septic field

• water flow

• slopes and natural features, e.g., creeks, rock outcrops, existing vegetation

• scale, North arrow, name, address

Take some pictures of your site as well.

1111

Design Considerations • Wildlife — attract (birds, butterflies, bees) or repel (deer, horses, bear)?

• Zonal Planting — group plants with similar water and light needs.

• Lawn — how much and where?

• Hardscape — fences, patios, paths, etc.

• Water feature — pond, pondless waterfall, bubbler, rain garden.

• Service areas — storage shed, kennel, space for garbage cans, etc.

• All season colour — evergreen trees and shrubs, ornamental grasses, bulbs, ground-

covers and perennials, deciduous trees and shrubs. Think about berries, foliage and

bark colour as well, not just flowering colour.

• Native plants — no plant material is more adapted to our semi-arid environment

than native species.

• Lighting or other electrical needs.

Tips for Low Maintenance Design • consider low-water lawn seed mixes, groundcovers and meadows

• use evergreen trees and shrubs

• use native plants and drought-tolerant plants that grow well in Bench soils

• plant in the fall

• use mass plantings

• allow room for mature shrubs and trees

• use perennials (vs. annuals), naturalizing bulbs and ornamental grasses

• use organic mulch to cover bare ground between plantings

Want some other ideas? Take part in a Meadowlark Festival ‘Xeriscape Garden

Tour’ held every year in May.

Landscaping information is widely available at public libraries and online (see

bibliography). Whenever possible do it yourself, but know when to hire a

professional, for example, with installation of rockwork, patios, and focal features.

Recycle materials and make use of natural or existing features already on your

property, for example, rocks, rock outcroppings, or native plants.

Soil Analysis and Soil Analysis and Soil Analysis and Soil Analysis and AmendmentAmendmentAmendmentAmendment

The West Bench consists primarily of dry, lacustrine silts, (see map opposite page),

deposited in glacial Lake Penticton during the retreat of the last phase of glaciation The soil

has slow drainage, weak soil structure, and is naturally low in humus (organic matter) and

nutrients. It is highly susceptible to erosion when excess water is applied.

Soil Variability Not all soils in the West Bench are silty; there are areas that are quite sandy or have a

high gravel content. It is important to determine the variability of the soils by digging several

test holes at various locations on your lot. The City of Penticton has created a detailed map

of soil variability; this map is available for viewing through the City.

Regardless of the soil type, most native soils in the West Bench area lack organic

matter. Residents are encouraged to create a subsurface environment that pro-

motes healthy plant development with deep root growth. This will both mitigate

the erosion hazards associated with soils that have a high silt content, and improve

the soil structure and absorption in sandy or gravelly soils.

Amending the Soil Adding organic matter is the best way to enhance moisture retention, improve soil

structure and add nutrients. Amending the entire planting area may not be realistic on the

large lots of the West Bench. So, it is recommended you choose plants that are adapted to

the natural soil, or lightly amend just the planting hole:

• dig a hole three times wider, but not deeper than, the plant root ball

• use organic matter such as compost or composted manure

• mix the compost into the native soil (25-30% by volume)

• don’t layer and don’t plant into only the amendment

• no need to amend the soil for native plants or plants that thrive in your soil type.

Sources of soil amendments include ‘backyard’ compost, landfill compost and bagged or

bulk compost or manures, available at local nurseries and garden centres.

2222

Lacustrine soils

with high silt

content (>80%)

occur through-

out the bench

lands of the

Okanagan,

especially in the

Penticton area,

and are highly

susceptible to

surface and

subsurface

erosion and

slumping,

predominantly

triggered by

groundwater

loading.

Practical Turf AreasPractical Turf AreasPractical Turf AreasPractical Turf Areas

Most lots on the West Bench consist primarily of

large lawns. Although there are benefits to having a lawn in

your landscape, large lawns have their drawbacks. They are

costly to establish and maintain — on the pocketbook, on

your yard time, and on the environment. As you redesign

your landscape ask yourself, “How much turf do I really

need?”

Conserving Resources on Your Turf Area 1. Keep your Kentucky Bluegrass lawn, but ...

• reduce the square footage

• change your watering habits (see page 23).

• “Gold is the New Green”: let the lawn go dormant

(brown) in the hot summer months.

2. Remove lawn and reseed with a low-water variety • try a blend of fescues (‘Eco-Lawn’ or ‘Enviroturf’),

buffalo grass, or a buffalo grass/blue grama grass combination.

• consider hydroseeding with a custom seed mix if you wish to reseed a large area

• low-water alternatives can be mowed or left to grow tall, forming a meadow.

Reseeding or overseeding lawn areas is less expensive than having turf installed.

3. Overseed existing lawn. • use a more drought-tolerant species (see ‘2’ above)

• prepare the existing lawn by: either (1) adding 3-4 inches of topsoil, or (2) cutting

the existing lawn as short as possible then use a power rake to roughen the turf and

expose soil so the seed can germinate

• overseed repeatedly over 2-4 years until the old lawn has been replaced.

Note: This is a great option for retaining organic nutrients in your soil.

4. Eliminate turf completely (see page 11). • use an alternative groundcover (wooly thyme, kinnikinnick, creeping juniper)

• Replace with other xeriscape options such as mixed planting beds or pervious

hardscape.

.

3333

�Domestic water

demands fluctuate

throughout the year

with maximum

demand being

experienced

during the summer,

primarily due to lawn

sprinkling.”

2005 WBID Drought

Management Plan

How to Remove TurfHow to Remove TurfHow to Remove TurfHow to Remove Turf

The prospect of removing a large amount of turf from the yard can be intimidating.

However, because reducing the amount of conventional lawn is the single, most effective way

to reduce water consumption, a number of ways to do so are included. In keeping with your

xeriscape plan, you can convert portions of your property one year at a time.

Sod Cutter A sod cutter is a gas-powered machine that is maneuvered much like a rototiller. The

height (depth of the cut) of the blade is adjustable. Sod cutters can be rented from local

rental centres.

Work together with your neighbours. After each landowner has determined where

grass will stay and where it will not, the group can hire a crew to remove five or six

lawns over a weekend. If you organize a work party, the contractors can remove the

turf as West Bench neighbours are loading it into a dump truck for composting at

the landfill. In exchange for turf, perhaps you can make an arrangement with the

Penticton Landfill for free compost to replace the organic material removed by the

sod cutter.

Advantages

- Removes most of the existing grass roots.

- Removes a thick layer of weed seeds.

- Lawn can be removed quickly.

Disadvantages

- Very hard, heavy work.

- Removes the organic, nutrient-rich layer of soil.

- Must remove sod under trees by hand to avoid root

damage.

Other Comments

- If you have underground irrigation, mark the sprayers to avoid damage.

- Exercise care when using a sod cutter on slopes or uneven ground.

- Cut the grass before you begin; remove the turf when it is not too wet.

- Try cutting in a diamond pattern; the turf is very heavy.

Credit: Toni Boot

Sheet Mulching or “Lasagna Gardening”

Sheet Mulching is a layered mulch system. It is

extremely inexpensive and easy to do. New plant-

ings can be planted through the mulch, but if

you’ve planned where you want to add vegeta-

tion, it’s easier to plant before sheet mulching.

A small area is left open to accommodate estab-

lished plants and trees.

Step 1: Prepare the site.

• Mow the lawn as short as possible.

• Remove healthy turf from areas where plants will be planted, allowing room for

development of roots. (Turf will not biodegrade under dry conditions.)

• Dig wide holes, add amendments if necessary, and plant. Water in the plant. • Lay a 1” layer of compost or manure to speed up the decaying process. • Soak the area with water.

Step 2: Add a weed barrier.

• Put down an organic weed barrier that is permeable to water and air.

• Recycled cardboard, a thick layer of newspaper, burlap bags or old carpets of

natural fiber work well. Do not use plastic.

• Two or three layers may be required to achieve a ½” thickness.

• Leave a generous opening for air circulation around the root crown of established

trees and shrubs.

• Wet down the weed barrier.

Step 3: Layer mulch.

• Good materials include chipped plant debris, tree

prunings, leaves or straw.

• The mulch layer should be 3-5” deep.

Step 4: Plant.

• If you did not plant in Step 1, punch a hole in the

cardboard and underlying turf . Remember to cut a

wide hole to accommodate root development.

Other Comments on Sheet Mulching

- Do not use sheet mulching over septic drainage fields.

- If your West Bench turf is healthy extra care must be taken to remove turf

where plants are to be planted (Step 1), or to delay planting until the turf is

thoroughly biodegraded (Step 4).

- If you are installing a drip irrigation system for the transformed area, place the

tubing on top of the weed barrier, and beneath the surface layer of mulch.

Soil Solarization Solarization is accomplished by completely covering an area with clear or black plastic

during July and August. The intense heat that builds up under the plastic kills the turf and

sprouting weeds.

Advantages

- Easy to do.

- Does not remove organic matter or

nutrients from the soil.

Disadvantages

- Can cause an anaerobic effect, killing

valuable microorganisms in the soil.

- Heavy winds can displace the plastic. Anchor

it with stones or wood.

- Is unsightly.

Other Comments

- Mow the grass as short as possible and water well before covering with the plastic.

The combination of heat and water introduces a fungus that speeds up turf

decomposition.

Photo: Lesley Field

Rototill

This method takes some patience, as you need to rototill several times. Between each

tilling, let the lawn sit four to six weeks to allow the grass and weeds to re-sprout.

Advantages Disadvantages

- Easier to maneuver than a sod - Area may be disrupted for

cutter. several months.

- Keeps the nutrients and organic - Cannot rototill near tree

matter in the soil. roots.

- Can damage the soil structure.

Other Comments

- Do not rototill if you have bindweed

(Convulvulus arvensis, see right) in your turf, or

any noxious weed that propagates by rhizomes.

- Unless you are certain your underground irriga-

tion system is deeper than the tines of the

rototiller, do not use this method.

- Mark sprinkler heads of underground irrigation

before beginning (see note above).

- Be prepared to spend time raking and leveling

the tilled area.

Spray with Herbicides If you are planning to overseed or reseed your existing turf, this method is an option to

consider closely. Use a mild herbicide, such as glyphosate (trade name ‘Round-up’) or

‘Eco-Clear’, a blend of acetic and citric acids. Always follow the label directions closely.

Advantages Disadvantages

- Little labour involved. - Herbicides are expensive.

- Kills weeds and turf. - May need several applications

- Keeps the nutrients and organic to kill some perennial weeds.

matter in the soil.

Other Comments

- Residential use of herbicides by other than certified pesticide applicators is

currently being reviewed in BC.

- Both recommended sprays are post-emergent, foliar products; they only work on

actively growing vegetation.

Plant SelectionPlant SelectionPlant SelectionPlant Selection

Selecting the right plant for the right location is very important. There is an exten-

sive list of plants suitable for the West Bench. The list, found on pages 31-35 includes plants

that thrive in silty soils, control erosion and/or are resistant to deer. They are all winter-

hardy to zone 5 and grow in dry to low-water conditions.

When selecting plants for your site it is also important to consider sun and wind expo-

sure. Plants can also be selected for their practical purposes. For

instance, shallow-rooted plants, such as grasses and certain herba-

ceous perennials, are good choices over septic drainage fields; like-

wise taller plants can create shade or provide screening. Remember

trees are an important part of xeriscape: they provide shade and

have a cooling effect on the home and the landscape.

Grouping Plants by Water and Sun Requirements (Zonal Planting) Picture your lot as an ‘oasis in the grassland’: the area clos-

est to your house (Zone 3) is the most lush and full. This

zone includes small turf areas and vegetable gardens. Fur-

ther from your house, but not on the peripheral of your

property, is Zone 2 which contains low-water plants that

benefit from occasional drip irrigation. Zone 1 is furthest

from your house and contains only those plants that do not

require supplemental irrigation, once established. This is an

excellent area to consider a native plant garden or habitat

restoration. As you are selecting plants, decide in which of

the three zones the plant will do best, based on its needs.

Zone 1 requires the least amount of watering and the least amount of mainte-

nance. On the large lots of the West Bench, this zone should be the largest zone.

Conversely, Zone 3, which requires the most care and watering, should be kept

small and practical.

4444

Zone 1 Dry ‘Natural’

Zone 2 Low-Water ‘Transition’

Zone 3 Moderate Water ‘Oasis’

Hand water until established

Micro/drip irrigation

Micro/drip irrigation (except for turf area).

Create an

‘oasis in the

grassland’.

Purchasing plants to fill a large-lot can become very expensive. Here are some tips for

obtaining plants on a low budget:

• Start your own plants from seed or trade xeriscape seeds, plant divisions and

cuttings with friends and neighbours. Have an annual plant trade day.

• Salvage native plants (with permission) from lands scheduled for development.

• Buy plants in the fall when they are usually at a discounted price.

• Bulk purchase plants together with neighbours; prepare beds before buying.

• Check with local nurseries to ask if they custom grow large orders.

• Buy your plants in the smallest sizes possible, such as in plugs. They are less

expensive and will more easily adapt to your soil conditions.

• Ornamental grasses and perennials are cheaper than shrubs and trees.

• Buy plants from the discount section of the nursery.

• For large areas or slope stabilization, choose native plants that spread.

• Plant perennials instead of annuals—you don’t have to replace them every year.

“Spread the Word — Not the Weed” The Invasive Plant Council of BC states that, among other problems, invasive plants

have the potential to decrease natural biodiversity and wildlife habitat, lower property values,

and hinder aesthetic appeal.

Simple Ways Gardeners Can Help:

• Choose plants wisely. Be suspicious of plants promoted as “fast spreaders” or

“vigorous self-seeders.”

• Do not purchase or grow invasive or legislated noxious weed seeds or plants.

• Dispose of invasives carefully: don’t ‘recycle’ garden debris or compost. Properly

dispose in trash bags for a local disposal facility/incineration, or by drying out any

material to kill remaining vegetative parts.

• Avoid letting invasive plants fruit or set seed, as birds and animals can spread the

plants to other areas. Remove flowers, seedpods, and berries of invasive plants.

• Avoid using exotic wildflower seed mixes.

• Avoid picking plants from roadsides, gravel pits or other disturbed areas.

• Discourage propagation of invasive species by friends and neighbours.

• Limit soil disturbance and cover bare soil on your property.

• Get involved with local efforts to control invasive plants.

• See page 35 for a list of locally invasive or potentially-invasive weeds.

• RDOS and the Invasive Council of BC have additional information and pictures.

(See Resources, page 36.)

Efficient IrrigationEfficient IrrigationEfficient IrrigationEfficient Irrigation

West Bench Irrigation District’s Drought Management Plan

states that during winter months, typical water demands are in

the order of 490 m3 per day. In summer, the irrigation demand

increases twenty-fold to 10,000 m3 per day. The maximum

summer demand is primarily due to lawn sprinkling. By simply

converting to efficient irrigation practices landowners can see a

dramatic reduction in water use.

Excessive irrigation not only wastes a valuable resource, it

can lead to soil saturation or groundwater loading. This addi-

tional water can be enough to increase the likelihood of pipe and

sinkhole developments or a major erosion event such as land-

slide.

Start with a Good Irrigation Design An irrigation system must be well designed and installed by

a licensed irrigator in order to be efficient and cost-effective. It is

important to review the West Bench irrigation bylaws and to

ensure that proper backflow prevention devices, valves and con-

nections are installed. The South Okanagan has many professionals certified by the Irriga-

tion Industry Association of BC to help you design and install an irrigation system that

works for you.

Start with a xeriscape plan, then hire a professional to cap unusable or unnecessary

portions of the underground system, and install a controller that allows for proper

water usage. From there, it is relatively simple for the homeowner to refit

sprinklers to micro or drip systems for xeriscape zones. For best results, hire a certified

irrigation professional who understands how to irrigate a xeriscape.

Zones Group your plants according to their watering requirements (see pg. 15). Not only will

this save water, it will prevent the need for complex or costly irrigation systems.

5555

�… increased

infiltration raises

the water table

so that a

smaller trigger-

ing event, such

as higher than

average rainfall,

is required to

induce a

landslide.”

1992 Klohn

Leonoff Report

When to Water You should only water your landscape when necessary. Keep an eye on your plants and

soil moisture to know when to water. This will vary depending on the current weather,

recent rainfall, time of year, and your specific soil types.

Generally, the leaves of shrubs and perennials will begin to droop, and lawn grass will

leave footprints when dry. If the top inch of soil next to a plant feels dry when you wiggle

your finger into it, this is another sign that water is needed. You can also use a shovel or a

soil probe to determine how dry the soil is.

It is best to water when the weather is cool, dark, humid and windless. At night or early

in the morning before sunrise are optimal times. Irrigation during these times also helps to

reduce interference with daytime household water and energy demand.

Watering Frequency For xeriscape plants, it is important to water deeply and infrequently. Soaking the soil

to the bottom of the root-zone encourages roots to grow into deeper soil, instead of spread-

ing into drier surface soil. Wait until the soil partially dries out before watering again.

Watering Depth and Rate

Soil Penetration For typical West Bench silty soils, one inch of water penetrates 6-10 inches. Silty

soils should be watered at a rate of approx ½ inch per hour. More than this may

lead to surface run-off and can lead to serious erosion problems Visible puddles

are a sign that the watering rate is too high; water pressure should be turned down,

or watering should be spread over a series of cycles. Run-off monitoring is

especially important on slopes.

Soil Type Penetration depth of 1” of

water (inches)

Infiltration rate of water

(inches /hr)

Clay 4-5 1/10 to ¼

Silt/loam 6-8 ¼ to ¾

Sand 12 -14 1-2

Watering New Plantings New plantings must be watered regularly until deep roots are established — the first year

for shrubs, and 2-3 years for trees. Water deeply, to the bottom of the root zone.

Irrigation Systems Irrigation systems can range from simply hand-watering your plants with a watering can

or hose nozzle, to complicated underground systems with timers and soil sensors. The most

efficient irrigation systems use nozzles that apply water directly to the soil in the root zone of

the plants needing water, with the least loss of water by evaporation. Low-flow systems, such

as “micro” or “drip” irrigation are very efficient.

Micro Irrigation Micro irrigation is highly recommended for xeriscape landscapes. This system includes

a flexible supply tube that lays on the soil surface, with individual emitters that supply each

plant. Landowners interested in this system can consult with local irrigation suppliers for

information before starting a project.

Benefits of Micro Irrigation • existing underground irrigation can easily be converted to drip or micro

irrigation

• very inexpensive, and extremely adaptable • less water is lost to evaporation; this is especially important for windy areas • emitters can be adjusted to the water requirements of each plant as it grows

• do-it-yourself landowners can easily purchase and install these systems

• irrigation timers and sensors can be included, but are not required

• well-suited system for plant beds in the low- and moderate-water zones

• the system is above ground, therefore leaks can be easily detected.

Before

��

After

After

Photos: Kevin Dunn

April

SeptemberJune

��

After

Before

��

Photos: Toni Boot

Basic Irrigation Schedule for Drip Irrigation Systems in West Bench

• These are general guidelines. Needs vary depending on weather, flow rates and soil.

• Figures based on ½ gph (gallons per hour) for perennials, 1 gph on shrubs, 3 gph

on large shrubs and 6 gph on mature trees.

• For automated systems, spread your daily allotment over 3 cycles during the day.

Watering By Hand For many garden areas, complex irrigation is not necessary, and hand-watering or

moving sprinklers will suffice. Plants in the dry or natural zone should not require regular

irrigation once they are established. Simply handwater these plants during the first year of

growth, then water only when necessary during extremely dry conditions in following years.

Smaller gardens, plants close to the house, or feature trees can also be watered by hand.

Plant Type Root

depth

(in.)

Avg.

water

needs

April, May, Oct June, Sept July, Aug

Hours Days/

week

Hours Days/

week

Hours Days /

week

Vegetables

and annuals 4-8 Mod 2 1 3 2 4 3

Perennials

8-12

Low 1.5 Every

2 wks. 2.5 1 2.5 2

Mod 2 1 3 2 4 3

Small shrubs

3-5 ft 12-24

Low 3 Every

2 wks. 4 1 4 2

Mod 4 1 5 2 6 3

Large shrubs

or small trees

5-10 ft 18-30

Low 5 Every

2 wks. 5 1 5 2

Mod 6 1 7 2 8 3

Mature trees

10-25+ ft 24-36

Low 5 Every

2 wks. 6 1 6 2

Mod 6 1 8 2 10 3

Hand or Sprinkler Watering for Larger, Mature Plants


• Determine the flow rate or your sprinkler or hose by submerging the sprinkler or

nozzle in a large bucket of known volume. Time how long it takes to fill the bucket

to determine your flow rate in gallons per minute or gallons per hour.

Lawn Irrigation Conventional sprinklers or underground irrigation are the normal systems for lawn

irrigation. There are also nozzles for micro irrigation systems suitable for small turf areas.

Application Rate Lawns benefit from approximately 1” of water for every irrigation. To determine how

many minutes you need to turn on your sprinklers:

• place straight-sided containers, such as tuna cans, around your lawn

• turn on the water for 15 minutes

• determine the average depth of water, in inches, in the containers

• calculate your flow rate in inches/minute: (avg. depth of water divided by 15 min.)

• to obtain 1 inch of irrigation, divide the number “1” by your flow rate. This is how

long you need to turn on your sprinklers to saturate the lawn to root depth.

Pooling water indicates the application rate is higher than the infiltration rate; adjust your

system accordingly.

The lawn should then be allowed to dry out a little between watering. Generally, once

the grass starts to lay flat, or footprints are left in the lawn when you walk across it, then it is

time to irrigate again.

Plant Type Root

depth

(in.)

Avg.

water

needs


Gallons Times

per

month

Gallons Times

per

month

Gallons Times

per

month

Small shrubs

3-5 ft 12-24 Low 5 0-1 5-10 1-2 5-10 1-2

Mod 5-15 1 10-20 2 10-20 2-3

Large

shrubs/small

trees 5-10 ft

18-30 Low 20-30 0-1 20-40 1-2 20-50 1-2

Mod 30-60 1 30-60 2 30-60 2-3

Mature trees

10-25 ft 24-36 Low 100-150 0-1 100-150 1-2 100-150 1-2

Mod 150-200 1 150-200 2 150-200 2-3

Recommended Watering Frequency for West Bench Lawns


Automatic Timers and Monitoring Weather Irrigation systems with automatic timers can help to reduce water use, but only if they

are adjusted regularly to prevent overwatering. Remember these systems are only as efficient

as the person who sets the timer! It is important to monitor your landscape and the weather

regularly so that you can reduce irrigation when there is sufficient rainfall. Soil moisture

sensors and shut-off devices can be installed to do this automatically. Visit www.farmzone.ca

and www.irrigationbc.ca for up-to-date, local weather information.

System Maintenance and Water Audits Your irrigation system should be monitored regularly to ensure proper functioning and

application rate. A yearly irrigation water audit by yourself or a contractor includes:

• checking for leaks and making sure valves open and close properly

• ensuring sprinklers are upright and the arc is correct

• clearing or changing blocked nozzles

• ensuring water is not falling on pathways, patios or driveways

• application rate is appropriate

• timers and sensors are functioning and set properly

Additional Thoughts in Reducing Irrigation in the West Bench • have water purveyor set up automatic systems

• install dole valves and flow restrictors at each property

• stagger the water fees (once meters are installed), based on water usage.

Grass Type Avg. Root

Depth

Water

Needs

Number of irrigations per month

1-inch of water per irrigation


Buffalo grass 6-8” Very low 0-1 1 1-2

Fescue (Ecolawn or

Enviroturf) 6-10” Low 1 2 2-3

Conventional

Bluegrass lawn 3-6” Moderate 1-2 2-4 3-4

Mulch Mulch Mulch Mulch

West Bench lacustrine silt is low in organic matter. When mulch is applied to this

type of soil, the increase of organic material: (1) enhances water absorption, and (2) slows the

rate of infiltration. Both these benefits reduce the risk of erosion.

Mulching is one of the best things you can do to ensure the health of your plants. There

are two general types of mulch: organic and inorganic.

Organic mulches consist of plant materials, such as: shredded bark, wood chips, chipper

debris, sawdust, wood shavings, dry grass clippings, pine needles, evergreen boughs, peat

moss, straw, compost, newspaper, shredded paper, leaves, and leaf mold. Inorganic mulches

consist of non-living materials, such as: plastic, woven fabrics, pea gravel, river rock, crushed

stone, and shale.

Benefits of Organic Mulch • limits reflectivity, keeping plants cooler and resulting in

less evaporation

• absorbs and retains water around root zones

• protects and insulates soil from freezing in winter

• controls erosion by slowing down rainwater

• reduces the loss of bare topsoil to wind

• safeguards against soil compaction and crusting

• builds soil, improving organic content and nutrients

• reduces weed growth and seed germination

• becomes a design element, giving the landscape a ‘finished’

look

• some mulches help acidify alkaline soils, such as coffee

grounds, evergreens, pine needles, and sawdust.

Inorganic Mulch

Inorganic mulches are long lasting and are good for high traffic areas such as pathways.

However, they can be hard to clean, expensive and difficult to weed.

Keep in mind that rock mulch, particularly in our hot Okanagan summers, can create

an additional stress on plants because of its tendency to both absorb and reflect heat, increas-

ing temperatures around your plants, your home and your neighborhood. The increased

heat results in a higher evapotranspiration rate, which leads to higher water demands. If you

plan on installing rock mulch, you are recommended to keep these features small.

Costs and Coverage • Recommended depth of mulch is 2 inches for fine

mulch to 4 inches for rough mulch.

• One cubic yard covers 108 sq. ft. in 3 inches of mulch.

• The cost of organic bark mulch ranges from $25 to $60

per yard ($0.25 – 0.60/sq. ft).

Mulch can be a major expense in creating new landscapes. However, it is possible

to obtain some mulches for free. Some free materials include grass clippings, pine

needles, leaves, chipper debris, cardboard and newspaper.

Mulching Tips • The best time to add mulch is just after planting. Top-up existing mulch in the fall.

• Locate flammable mulches such as pine needles, straw and evergreen boughs away

from wooden walls and fences. Once organic mulches have aged and flattened

down, they are much less flammable.

• Do not bury stems or trunks of trees, shrubs, and woody perennials; this avoids pest

or fungal problems.

• Mulch containing strips of bark or different size chunks tends to knit together

better to withstand wind.

• Plastic landscape fabric under organic mulch is not recommended. Plastic prevents

water infiltration and weeds will eventually grow through this layer. If troublesome

weeds occur in this area, consider sheet mulching.

• It is always best to cover bare soil with mulch, even if you are not ready to plant.

This will save weeding time.

• Extremely dry soil plants such as cacti, succulents, and artemesias are sometimes

better left without mulch.

Mulching is one

of the best

things you can

do to reduce soil

erosion.

MaintenanceMaintenanceMaintenanceMaintenance

Large West Bench properties can be time-consuming and costly to manage.

Although every landscape requires some maintenance the advantage of xeriscape is that

much less time, money and resources need to be expended to keep your landscape beautiful

and healthy.

Irrigation • Perform watering system audit. See page 24.

• Monitor for signs of erosion caused by irrigation leaks or run-off.

• By overwatering your landscape, plants stay healthy and require less care.

Lawn Care • Fertilizing a low-water lawn should only be done once annually, in the spring.

Lightly topdress your lawn with compost or a nutrient-rich soil.

• Overwatering and/or overfertilizing conventional lawns necessitates more frequent

mowing, dethatching and aerating. Reducing both cuts down on your maintenance

time.

• A healthy lawn is naturally more resistant to weed growth.

Weeding • Stay on top of weeding. This task is much reduced when mulch has been applied.

Pruning • Prune out dead, diseased and damaged limbs.

• Trees should be pruned when they are dormant.

• Proper watering and fertilization practices, and allowing room for mature species,

can virtually eliminate the need to prune.

Fertilizing • For the most part, xeriscape plants do not require

the application of fertilizer, particularly if you’ve

amended the soil.

• Do not fertilize native plants.

Mulching • Top up mulch when necessary.

7777

Photo: Grasslands Nursery

Managing and Using Rainwater Runoff Managing and Using Rainwater Runoff Managing and Using Rainwater Runoff Managing and Using Rainwater Runoff

Rainstorms can be few and far between in the arid Okanagan Valley. However, when

they do arrive, the rapid flow of surface waters can cause serious erosion problems in the

West Bench area such as gully erosion, underground piping, sinkhole formation, and

landslides. Sudden rainfall is often viewed as a hazard, but with a few simple preparations,

rainwater can be turned into a valuable resource for landscape irrigation.

Steps to Harvesting Rainwater

Begin with long and thoughtful observation.

• Observe where the water flows, where it collects, where it drains away, and where it

drains from. This informs you of your resources and challenges. Build on what is

working and change what isn’t.

Start at the top of your property or house, and work your way down.

• It is easier to harvest water at the top where it is more manageable. Then use the

free power of gravity to distribute harvested water to areas down slope.

Start small and simple.

• Small, simple systems of an appropriate scale are easier to create and maintain than

complex, extensive systems. Start with a rain barrel off one downspout or create a

berm around a large tree where runoff occurs.

Slow, spread, and infiltrate the flow of water.

• A zigzag pattern calms the flow of water to reduce destructive erosion and increases

the time and distance the water flows. This will improve infiltration into the soil

from the high point to the low point. For example, creating a system of small berms

or terraces on steep slopes helps to slow flow of water.

Always plan an overflow route and manage that overflow as a resource.

• You can’t turn off the rain once your water-harvesting earthworks and cisterns are

filled up, so always be prepared for overflow into the surrounding landscape.

Create a living sponge.

• Maximize planting of appropriate vegetative groundcover and spread organic

mulch over the surface of the soil to create a “living sponge”. As roots expand and

soil life increases, the soil’s ability to infiltrate and hold water steadily improves.

Continually reassess your system.

• Monitor the success and failures of your rainwater systems. If necessary, make

changes using the above steps to guide you.

Tips • Do not infiltrate water within 10 feet of a building

foundation.

• Always check for underground utility lines before

digging.

• Harvest water into the moderate-water or oasis zone,

where the plants need it most.

• Make sure land slopes away from all buildings.

• Don’t move large quantities of soil; instead, work

with the existing landscape forms.

• Direct downspouts or rain barrel overflows onto

high points, so that gravity can be used to distribute

the water throughout the site via berms and basins.

Driveway Runoff • Reduce the amount of impervious, paved surface on your property.

• Slope pavement to drain into vegetation alongside

driveway.

• Cut grooves or create small speed bumps to divert

water towards plantings.

• Use small berms alongside driveway to catch and

hold water around plants.

• Install drain tile or a French drain at the bottom of

a long slope in the driveway to divert water to the

sides rather than onto the main road.

• Consider installing porous surfaces for driveways and paths such as gravel, recycled

asphalt, porous asphalt, open-jointed blocks or turf blocks.

• Reduce the driveway to two narrow strips for vehicle tires.

Roof Runoff • Install rain barrels at the bottom of downspouts to hold water for irrigation on dry

days. Be sure to install an overflow route for water.

• If downspouts empty onto steep, erodible slopes, install a rock spillway (dry creek

bed) or pipe to carry water to your landscape.

• Install rain chains instead of downspouts.

Illustrations: Joe Marshall

• Use a perforated pipe on the end of downspouts to distribute water away from the

house and towards plantings.

• Install 3-4 pop-up drains per downspout, which distribute roof runoff onto your

landscape.

• Install a green roof to absorb and slow down rainfall while moderating the tempera-

ture of your home.

Landscape Features to Capture, Distribute, and Infiltrate

Rainwater

Berms and Basins

A system of small berms and basins, also known as ‘ditch

and swale’, can be used on moderate slopes to slow, disperse

and allow water to infiltrate the soil. A berm generally fol-

lows a contour line of a slope, or forms a boomerang shape

to hold water around a specific plant. A basin consists of a

depression in the ground that catches water and allows it to

infiltrate the soil. Basins usually contain deep-rooted plants to

soak up the rainwater, essentially functioning as a ‘rain garden’.

Terraces

A terrace is a flat shelf of soil built parallel to the contour of a

slope, creating flat planting areas. These are typically used for

smaller gardens on steep slopes.

Spillways

Spillways carry water from down-

spouts or overflow areas towards collection basins. Spillways

should be lined with plastic and artfully covered with rock to

form an attractive dry creek bed, thus adding a design

element to your landscape.

French Drain

A French drain is a plastic-lined basin or trench filled with angular gravel. This allows

water to infiltrate quickly, while creating a stable surface on which to walk. French drains

can be used to carry water away from non-porous surfaces to

catch basins surrounding shrubs and trees. Illustrations: Joe Marshall

PLANT LIST PLANT LIST PLANT LIST PLANT LIST

PLANT NAME

SS EC

NATIVE GRASSES

Great Basin Wild Rye

Elymus cinereus x x x

Idaho Fescue

Festuca idahoensis x x x

Needle and Thread Grass

Hesperostipa comata x x

Junegrass

Koeleria macrantha x

Bluebunch Wheatgrass

Pseudoroegnaria spicatum x x x

Sandberg's Bluegrass

Poa secunda x x x

NATIVE PERENNIALS

Yarrow Achillea millefolium x x x

Nodding Onion

Allium cernuum x x

Pearly Everlasting

Anaphalis margaritacea x x

Kinnikinnick

Arctostaphylos uva-ursi x x x

Pasture Sage Artemisia frigida x x x x

Western Mugwort

Artemisia lucoviciana x x

Showy Milkweed

Asclepias speciosa x x x

Tufted White Prairie Aster

Aster ericoides x x

Arrow-leaved Balsamroot

Balsamorhiza sagittata x x

Sulphur Flowered Buckwheat

Eriogonum umbellatum x x x

Parsnip-flowered Buckwheat

Eriogonum heracleoides x x x

X PLANT NAME

SS EC

NATIVE PERENNIALS

Snow Buckwheat

Eriogonum niveum x x x

Brown-eyed Susan

Gaillardia aristata x x

Prairie Smoke Geum triflorum x x

Golden Aster

Heterotheca villosa x

Round-leaved Alumroot

Heuchera cylindrica x x

Bitterroot Lewisia rediviva x

Blue Flax Linum perenne x x

Silky Lupine Lupinus sericeus x x

Shrubby Penstemon

Penstemon fruticosus x

NATIVE SHRUBS

Saskatoon

Amelanchier alnifolia x x x

Big Sagebrush

Artemisia tridentata x x x x

Red Stemmed Ceanothus

Ceanothus sanguineus x x x x

Snowbrush

Ceanothus velutinus x x

Rabbitbrush

Chrysothamnus nauseosus x x x x

Wolf Willow

Eleagnus commutata x x x

Ocean Spray

Holodiscus discolor x

Common Juniper

Juniperus communis x x

X

= Dry = Low-Water SS = Silty Soils EC = Erosion = Deer

X

Note: “x” in a column means suitable

PLANT NAME

SS EC

NATIVE SHRUBS

Oregon Grape Holly

Mahonia aquifolium x x x x

Mock Orange

Philadelphus lewisii x x x x

Shrubby Cinquefoil

Potentilla fruticosa x x

Antelope Brush

Purshia tridentata x x

Smooth Sumac Rhus glabra x x

Waxy Currant Ribes cereum x x x

Prairie Rose Rosa woodsii x x x x

Blue Elderberry

Sambucus caerulea x x x x x

Soopalallie

Shepherdia canadensis x x x x

Snowberry

Symphoricarpos albus x x x x

NATIVE TREES

Douglas Maple Acer glabrum x x x

Rocky Mountain Juniper

Juniperus scopulorum x x x

Ponderosa Pine

Pinus ponderosa x x x

Chokecherry

Prunus virginiana x x

Douglas Fir

Pseudotsuga menziesii x x

XERISCAPE BULBS

Crocus Crocus x x x

Snowdrop Galanthus x

Grape Hyacinth Muscari x x x

Daffodil Narcissus x x x

X PLANT NAME

SS EC

XERISCAPE BULBS

Prairie Crocus/Pasqueflower

Heterotheca villosa x

Scilla Scilla siberica x x

Tulip Tulipa x

XERISCAPE VINES

Jackmanii Clematis

Clematis jackmanii x x

White Clematis

Clematis ligusticifolia x x

Golden Clematis

Clematis tangutica x x

Grape Vitis x x x

XERISCAPE GRASSES

Big Bluestem

Andropogon gerardii x x

Bulbous Oat Grass

Arrhenatherum bulbosum x x

Blue Grama Grass

Bouteloua gracilis x x x

‘Karl Foerster’ Feather Reed

Grass

Calamagrostis x acutiflora ‘Karl’

Foerster’

x x

XERISCAPE GRASSES

Northern Sea Oats

Chasmanthium latifolium x x

Fescue Festuca x x x x

Blue Oat Grass

Helictotrichon sempervirens x x

Blue Hair Grass

Koeleria glauca x

Maiden Grass Miscanthus x x x

X

PLANT NAME

SS EC

XERISCAPE GRASSES

Switch Grass

Panicum virgatum x

Perennial Fountain Grass

Pennisetum alopecuroides x

Hardy Pampas Grass

Saccharum ravannae x

Little Bluestem

Schizachyrium scoparium x

Autumn Moor Grass

Sesleria autumnalis x x

Prairie Dropseed

Sporobolus heterolepis x x x x

Mexican Feather Grass

Stipa tenuissima x x x

XERISCAPE PERENNIALS

Hyssop Agastache x x

Hollyhock Alcea rosea x x x x

‘Mountain Gold’ Alyssum

Alyssum montanum ‘Mtn. Gold’ x

Mt. Atlas Daisy

Anacyclus depressus x

Windflower Anemone sylvestris x x x

Pussytoes Antennaria x x

Thrift Armeria maritima x

Sage varieties Artemisia x x

Aster Aster x

Hardy Gazania

Gazania linearis x

Cranesbill Geranium x x x x x

Rock Rose

Helianthemum numularium x x

Maximillian Sunflower

Helianthus maximillianii x

X PLANT NAME

SS EC


Basket of Gold

Aurinia saxatilis x

False Indigo

Baptisia australis x x x

Poppy Mallow/Winecup

Callirhoe involucrata x

Bellflower Campanula x x

Cupid’s Dart

Catanache caerulea x

Blue Leadwort

Ceratostigma plumbagnoides x x

Large-flowered Coreopsis

Coreopsis grandiflora x x x

‘Zagreb’ Threadleaf Tickseed

Coreopsis verticillata ‘Zagreb’ x x x

Hardy Iceplant Delosperma x

Pinks Dianthus x x x

Dragon’s Head Dracocephalum x

Purple Coneflower

Echinacea purpurea x x

Daisy Erigeron species x

Blanket Flower (variety)

Gaillardia grandiflora x

Daylily Hemerocallis x x

Candytuft Iberis semervirens x x

Iris Iris x x x x

Torch Lily Kniphofia x x x

English Lavender

Lavandula angustifolia x x

Shasta Daisy

Leucanthemum x superbum x x

Dotted Gayfeather

Liatris spicata x x x

X

PLANT NAME

SS EC


Catmint Nepeta x x x

Ozarks Sundrop

Oenothera macrocarpa

x

Penstemon (most)

Penstemon x x

Russian Sage

Perovskia atriplifolia x x

Fleeceflower Persicaria affinis x x

Phlox (some species)

Phlox subulata

x

Rosemary

Rosemarius officinalis

x

Gloriosa Daisy Rudbeckia hirta x x

Sage (many species) Salvia* x x x x

Alpine Skullcap

Scutellaria alpina x

Stonecrops Sedums x x

Hen and Chicks Sempervivum x

Thyme Thymus x x

Wooly Veronica

Veronica pectinata x x x x

‘Golden Sword’ Yucca

Yucca filamentosa ‘G. Sword’ x x

Soapweed Yucca glauca x x

XERISCAPE SHRUBS

Japanese Barberry

Berberis thunbergii

x x x

Bluebeard/Blue Mist Spirea

Caryopteris x clandonensis

x

Smokebush Cotinus x x

Cotoneaster Cotoneaster x x x

Euonymus (some varieties)

Euonymus*

x x

X PLANT NAME

SS EC


Apache Plume

Fallugia paradoxa

x

Forsythia Forsythia x x x x

Broom Genista x

Juniper Juniperus x x

Honeysuckle (shrub varieties)

Lonicera

x

Ninebark

Physocarpos opulifolius x x

Mugho Pine Pinus mugo x x x x

Staghorn Sumac Rhus typhina x

Currant/Gooseberry Ribes x x

Red Leaf Rose Rosa rubrifolia x x

Rugosa Rose Rosa rugosa x x

Dwarf Arctic Willow

Salix purpurea ‘Nana’ x x x

Lavender Cotton

Santolina chamaecyparissus

x x

Bridal Wreath Spirea

Spirea x vanhoutii

x x

Lilac Syringa x x x x x

Weigela Weigela florida x x x

XERISCAPE TREES

Maple (some varieties) Acer* x x x

Western Redbud

Cercis occidentalis

x x x

‘Paul’s Scarlet’ Hawthorn

Crataegus oxycantha

‘Paul’s Scarlet’

x x x

Green Ash

Fraxinus pennslvanica

x x x x

X

PLANT NAME

SS EC

XERISCAPE TREES

Maidenhair Tree

Ginkgo biloba x x

Honey Locust Gleditsia x x

Golden Raintree

Koelreuteria paniculata x

‘Colorado Blue Spruce

Picea pungens ‘Glauca’ x x

London Plane Tree

Platanus x acerfolia x

Gambel Oak Quercus gambelii x

Greenspire Linden

Tilia cordata x x x

Wayfaring Tree

Viburnum lantana x x x x

X

Baby's Breath (Gypsophila paniculata)

Bachelor's Button (Centaurea cyanus)

Black Locust (Robinia pseudoacacia)

Butterfly Bush (Buddleia davidii)

Canada Thistle (Cirsium arvense)

Cherry Laurel (Prunus laurocerasus)

Common European Hawthorn (Crataegus monogyna)

Common Fennel (Foeniculum vulgare)

Common Periwinkle (Vinca minor)

Common Tansy (Tanacetum vulgare)

Dalmatian Toadflax (Linaria genistifolia

spp dalmatica)

English Ivy (Hedera helix)

European Mountain Ash (Sorbus aucuparia)

Hawkweeds (Hieracium spp.)

Herb Robert (Geranium robertianum)

Hoary Alyssum (Berteroa incana)

Hound's-tongue (Cynoglossum officinale)

Invasive Knotweeds (Fallopia or Polygonum spp.)

Knapweeds (Centaurea spp.)

Leafy Spurge (Euphorbia esula)

Old Man's Beard (Clematis vitalba)

Oxeye Daisy (Chrysanthemun leucanthemum)

Puncturevine (Tribulus terrestris)

Purple Deadnettle (Lamium amplexicaule)

Purple Loosestrife (Lythrum salicaria)

Reed Canarygrass (Phalaris arundinacea var. picta)

Rush Skeletonweed (Chondrilla juncea)

Russian Olive, Oleaster (Elaeagnus angustifolia)

Scotch Broom (Cytisus scoparius)

Sea Buckthorn (Hippophae rhamnoides)

Siberian Elm (Ulmus pumila)

Silver lace vine (Polyganum aubertii)

Sulphur Cinquefoil (Potentilla recta)

Tamarisk, Saltcedar (Tamarix ramosissima)

Tree of Heaven (Ailanthus altissima)

Velvetleaf (Abutilon theophrasti)

Wild four o'clock (Mirabilis nyctaginea)

Yellow or False Lamium (Lamium galeobdolon)

Yellow Starthistle (Centaurea solstitialis)

Locally Invasive or PotentiallyLocally Invasive or PotentiallyLocally Invasive or PotentiallyLocally Invasive or Potentially----

Invasive SpeciesInvasive SpeciesInvasive SpeciesInvasive Species

Photo: Grasslands Nursery

Resources Resources Resources Resources (also see Bibliography)(also see Bibliography)(also see Bibliography)(also see Bibliography)

Bennett, Jennifer. Dryland Gardening:Plants That Survive and Thrive in Tough Conditions.

Richmond Hill, On. Firefly Books Ltd. © 2005.

Bonnemaison, Tamara. Native Plant Landscaping for the South-Okanagan

Similkameen. Osoyoos Desert Society, Osoyoos BC. 2008.

Dunnett, Nigel and N. Kinsgsbury. Planting Green Roofs and Living Walls. Timber Press Inc.

Portland, Oregon. © 2008

Ellefson, Connie, T.Stephens, D. Welsh. Xeriscape Gardening: Water Conservation For The

American Landscape. MacMillan Publishing Company, © 1992.

Hansen, Juergen and Jacquie Tapping. Gardening in the Okanagan. Okanagan Past and

Present Society 4th edition, Summerland. © 1995

Lang, Susan. Garden Watering Systems. Sunset Publishing Corp., CA, © 1999

Rummary, Mark. The Dry Garden: A Practical Guide to Planning and Planting. Sterling Publish-

ing, New York. © 1995

Soderstrom, Neil. Deer Resistant Landscaping. Rodale Inc. New York. © 2008

Springer, Lauren. Waterwise Gardens. Prentice Hall General Reference. 1994

Taylor, Jane. Drought Tolerant Plants: Waterwise Gardening for Every Climate. Prentice Hall

General Reference, New York. © 1993

Taylor's Guide to Water-Saving Gardening. Boston: H. Miflin. 1990.

Weinstein, Gayle. Ortho’s All About Dry Climate Gardening. Meridith Books, Des Moines, IL.

© 2004

Xeriscape Color Guide: 100 Water-wise Plants for Gardens and Landscapes. Ed., David Winger,

Denver, CO. Fulcrum Pub. 1998.

Sampling of Xeriscape Websites Okanagan Xeriscape Association http://okanaganxeriscape.org

Summerland Ornamental Gardens

http://www.summerlandornamentalgardens.org/xeriscape

Xeriscape Colorado http://coloradowaterwise.org

Bluestem Nursery http://www.bluestem.ca

Wildflower Farm http://www.wildflowerfarm.com

Irrigation and Water Conservation Websites

Farmzone http://www.farmzone.com

Irrigation Industry Association of BC http://www.irrigationbc.com

Landscape Watering Guide, Arizona http://www.wateruseitwisely.com/region/arizona/100-

ways-to-conserve/outdoor-tips/landscape-watering-guide.php

NDS Water drainage equipment and information. http://www.ndspro.com

City of Penticton Water Talk Newsletter

http://www.penticton.ca/city/public_works/water/default.asp

Invasive Plant Websites

Regional District Okanagan-Similkameen http://www.rdos.bc.ca

Invasive Plant Council of BC http://www.invasiveplantcouncilbc.ca

Xeriscape Designers

Grasslands Nursery, Toni Boot, 250-494-4617

Eva Durance, 250-492-0158

Waterwise Landscape Design, Lisa Masini, 250-862-1931

Xeriscape and Native Plant Selection

Grasslands Nursery, 3615 Gartrell Road, Summerland, BC, 250-494-4617

Sagebrush Nursery, 93rd St. #38084, Oliver, BC, 250-498-8898

Xeriscape Landscape Installers

Grasslands Nursery, Steve Burritt, 250-494-4617

Summerland Senior Services, Craig Whitehouse, 250-494-8333

Certified Irrigation Contractors

Emerald Irrigation, Aran Boyle, 250-490-9002

Grasslands Nursery, Steve Burritt, 250-494-4617

BibliographyBibliographyBibliographyBibliography

Boot, Toni. Xeriscape Seminar Series. Grasslands Nursery, Summerland BC.

C.R. Elevitch and K.M. Wilkinson. Sheet Mulching: Greater Plant and Soil Health for Less Work,

Permanent Agriculture Resources.

Drip Watering Made Easy. 7th ed. Raindrip, Inc. Fresno, CA. 2007.

Durance, Eva. Cultivating the Wild: Gardening with Native Plants of British Columbia’s Southern

Interior and Eastern Washington. Nature Guides BC. © 2009.

Ellefson, Connie and D. Winger. Xeriscape Colorado. Westcliffe Publishers. 2004.

Geoff Hall. Sheet Mulch. Sentient Landscape, Inc.

Lancaster, Brad. Rainwater Harvesting For Drylands and Beyond. Rainsource Press, Tuscon, AZ

© 2008.

Landscape Watering Guide. Water – Use it Wisely. Arizona.

http://www.wateruseitwisely.com/region/arizona/100-ways-to-conserve/outdoor-tips/

landscape-watering-guide.php

Pittenger, Dennis R. When and How to Amend Landscape Soils. University of California

Cooperative Extension, Southern Region.

Steele, Gwen and L. Masini. “Gardening with Nature”. 2009. Okanagan Xeriscape

Association. http://okanaganxeriscape.org

Weinsten, Gayle. Xeriscape Handbook: A How-to Guide to Natural, Resource-Wise Gardening.

Golden, CO. Fulcrum Pub. 1999.

West Bench/Sage Mesa Area Geological Hazards Review. Klohn, Leonoff Ltd., 1992.

Williams, Sara. Creating the Prairie Xeriscape: Low-Maintenance, Water-Efficient

Gardening. University Extension Press, University of Saskatchewan. © 1997.

A

about this publication, 2

how to print, 2

icons, 2

amending and analyzing soil, 8

B

berms and basins, 30

bibliography, 38

C

compost, 8, 25

E

erosion, 2, 4

amending soil to reduce, 8

and irrigation, 17

hazards 2, 4, 17

maintenance to monitor, 27

mulching to reduce, 25

plant selection, 15, 31-35

F

French drain, 30

H

herbicides, 14

hydroseeding, 10

I

icons, 2

inorganic mulch, 25-26

introduction, 4

invasive plants, 16, 35

irrigation

automatic timers, 24

design, 17

lawn, 23

micro/drip, 19

schedules, 17, 22-24

system maintenance, 24, 27

using rainwater runoff, 30

zones, 17

irrigation schedule

for micro/drip irrigation, 20

for hand or sprinkler 23

for West Bench lawns, 24

K

Kentucky Blue Grass

alternatives, 10

reduction, 10

L

lacustrine silts or soils, 4, 8, 25

map, 9

lasagna gardening, 12-13

lawns

conserving resources, 10

M

maintenance of xeriscape, 27

fertilizing, 27

irrigation, 27

lawn care, 27

mulching, 27

pruning, 27

weeding, 27

micro irrigation, 19

mulch, 25

cost estimates, 26

organic vs. inorganic, 25

O

organic mulch, 25

P

planning xeriscapes, 6

base plan, 6

design considerations, 7

low maintenance tips, 7

resources, 7

what to plant first, 6

planting, 15

grouping, 15,17

zonal planting, 15

plants

buying, 17

invasive, 16, 35

planting strategies, 15

selection, xeriscape, 15–16

for West Bench, 31-35

R

rainwater runoff, 29, 31–32

Real Estate Foundation of BC, 40

resource list, 36-37

rototilling for turf removal, 14

S

septic drainage fields, 14

sheet mulching, 12-13

sod cutters, 11

soils

amendment and sources, 8

analysis, 8

of the West Bench, 8

variability, 8

spillways, 30

T

terraces, 30

turf

benefits vs. drawbacks, 10

eliminating, 10, 11-14

irrigation costs, minimizing, 10

overseeding, 10

practical turf areas, 9

removing, 11

turf removal methods

herbicidal spraying, 14

rototilling, 14

sheet mulching, 12-13

sod cutting, 11

soil solarization, 13

W

water audits, 24, 27

watering

by hand, 22

depth, 18

frequency, 18

irrigation systems, 19-24

zones, 17

weeds

barrier, 13

growth control, 25

invasive, 16, 35

West Bench Irrigation District,

2, 5, 40

X

xeriscape

on the West Bench, 5

xeriscape principles, 5

efficient irrigation, 17

maintenance, 27

mulch, 25

planning and design, 6

plant selection, 15

practical turf areas, 10

soil analysis and amendment, 8

INDEX

The Large Lot Xeriscape Design Project is jointly funded by the West Bench Irrigation

District and the Real Estate Foundation of British Columbia, a non-profit corporation that

provides funding to support sustainable real estate and land use practices for the benefit of

British Columbians. Written by Toni Boot and Janelle Parchomchuk, this manual, Xeriscape

Design Projects for Large Lots: Solutions to the Challenges of Landscaping on the West Bench, is the

culmination of the Large Lot Xeriscape Design Project.

xeriscape design concepts for large lots solutions to the challenges of landscaping on the west...

Education

irrigation design

west bench irrigation

xeriscape design concepts

erosion of west bench

west bench area of penticton

design considerations

thewest bench

xeriscape manual