everything you ever wanted to know about pruning trees, shrubs and perennials but was afraid to ask

EVERYTHING YOU EVER WANTED TO KNOW ABOUT PRUNING…

BUT WERE AFRAID TO ASK Basics for residential light tree, shrub and perennial

pruning.

Jeff GriffPresident Lowe’s Greenhouses

YOU’RE JUST A SNIP AWAY FROM PERFECTION!

BEFORE I FORGET…

In my experience, working in the garden center, the most frequently asked questions are about pruning.

Why do you think that is?

They say that the most common fear is that of public speaking …

…followed closely by the fear of killing your plants by pruning incorrectly!

Now, of course, you are an exception to the rule being gardening experts. I would guess that you actually like to prune and enjoy this leisure time activity.

The reality is that, typically, when we offer pruning classes, it is generally populated by women who then….

…send this guy out to do the pruning.

Few homeowners understand pruning and, unfortunately, many landscape professionals lack this skill as well.

The fear of pruning is so prevalent it has even been featured in many Hollywood motion pictures.

17650 Elm Street

#1 Light tree pruning and young tree training #2 Shrub pruning#3 Perennial pruning

But let’s be realistic!

Pruning is an art form that can’t be simply communicated in a classroom setting. It is a lifelong pursuit of gathering a combination of plant knowledge as well as gauging cause/affect results from various techniques, timing and ever-changing environmental conditions.

#1 LIGHT TREE PRUNING (AND YOUNG TREE TRAINING)

Pruning is not like Red Bull…it does not give you wings!!!

The first thing to know is your plant’s tendencies. What is its natural shape and growth rate? What are its features and benefits.

What are we looking to do?*Remove dead, damaged or diseased branches.*Enhance tree structure and reduce risk of future branch damage/failure.*Promote healthy and attractive growth.*Enhance flowering and/or fruit production.*Eliminate rubbing/competing branches.*Remove co-dominate stems.*Extend life of landscape plants.

You may end up finding this information most helpful when selecting new tree specimens.

When is the time to prune?What is the desired effect?*Maximize growth: in early spring.*Minimize risk of pest and decay: during dormancy.*Minimize effect on fruit/flowers: immediately after flowering.

***Timing may not be an option when pruning storm damage or when eliminating hazardous branches.

STRUCTURAL PRUNING*Removing dead, broken or damaged branches.*Selecting a dominate leader or multiple strong leaders . (not all trees have a central leader) *Select the lowest permanent branches.*Select scaffold branches that are spaced evenly both vertically and radially.*Identify temporary branching for energy production and protection.***Do not remove any more than 25% of a tree canopy per season.

CODOMINANT STEMS*Are forked branches of similar size lacking a normal branch union.*Frequently forms a weak point of tree with included bark. (Bark embedded in crotch of tree) ***Not all trees have a single dominant leader.

CROWN CLEANING*Removing dead, diseased, rubbing, competing and broken branches.*Cleaning can be done at almost any time of wear.

CROWN THINNING*Removal of branches to improve light penetration and air circulation.*Reduces risk of storm damage.*Shows off trunk form and/or attractive bark.*Be careful not to be too aggressive.

Much of the most important pruning on trees will be done when they are very young so selection and training are very important for a long and care-free life.

GOOD

#2 SHRUB PRUNING

*Shrubs stand to gain the most from proper pruning techniques.*Fast pruning is easy to learn, easy to do and easy to sell.*Pruning is often done in late summer when it is convenient for landscape companies. (A perfect time to cut off newly formed flower buds.)*Proper pruning takes time, patience, knowledge and (when done correctly) is not easily detected.

Remember…good pruning cannot make up for bad design!!!

PRUNING LAWS, PRACTICES, PRINCIPALS AND… OTHER STUFF

*Pruning stimulates growth from the point of pruning.*Shearing and pruning are not the same.*Prune spring flowering shrubs immediately after flowering. (Flower buds are formed during previous summer)*Prune summer blooming shrubs during dormancy.*Trimming can be done any time.*Know what plants bloom on old growth and new growth.*Know your plants. Consider getting professional assistance to help identify your specific pruning needs.

How are your shrubs are like Olympic athletes?

You have to know what kind of shape you’re in!It is to your and the plants benefit to accentuate natural plant growth instead of fighting against it.

Another very important detail is to understand your plants potential growth rate.

Gold Mop Cypress

There is only 1 pruning method that is effective in this scenario!

A 40 year old landscape planting.

DO PLANT TAGS LIE?

Now let’s look at some shrub pruning techniques.

THINNING OR GRADUAL RENEWAL PRUNING

Examples of common shrubs that benefit from gradual renewal or thinning: Aronia, Clethra, Deutzia, Forsythia, Itea, Lilac, Mockorange, Potentilla, Spirea, Viburnum, Weigelia.

NOT SO GRADUAL RENEWAL PRUNING

Shrubs that generally respond well to complete renewal pruning:Aronia, Clethra, Cornus (shrub forms), Deutzia, Forsythia, Hydrangea paniculata, Itea, Mockorange, Potentilla, Privet, Spirea, Taxus, Viburnum, Weigelia.

SHEARING

Common shrubs that are often sheared:Azalea, Barberry, Boxwood, Burning Bush, Forsythia, Hibiscus, Lilac (Dwarf), Privet, Taxus.

HOW HARD DO YOU WANT TO WORK?

HOW DO YOU HEDGE?

Sheared plants need to be periodically thinned to allow light to penetrate the outer shell of foliage. As a rule, shear twice, prune/thin once.*(*Ideally done in late fall to allow snow penetration)

AND FINALLY… THE MOST FRQUENTLY ASKED QUESTION ABOUT PRUNING IS:

Hydrangea paniculata (Cone shaped, summer flowers)

Easy to bloom, hard renewal prune in dormancy. *Trimming a 2nd time in early summer can also be

helpful in certain situations.*Certain cultivars respond better to mid-season

trimming.

Oak Leaf Hydrangea quercifolia (Large leaves, summer bloom)

Thin as needed or prune hard to renew.

Hydrangea macrophylla (Big leaf Hydrangea)

Some bloom on old wood, others on new so it is important for you to know what you have and prune accordingly. When in doubt, do not cut all the way down and protect stems from freeze and frost.

Snowball Hydrangea arborescens (Soft leaves, round flowers in summer)

For best results, complete renewal pruning every year.

#3 PERENNIAL PRUNING

Color is king!

WHY IS PERENNIAL PRUNING IMPORTANT?

*MORE COLOR BOTH IN FLOWERS AND FOLIAGE.*EFFECTIVE AND ORGANIC INSECT AND DISEASE CONTROL. *IMPROVES OVERALL GARDEN APPEARANCE.*SAVES WORK AND TIME IN THE GARDEN.

There are many pruning techniques to enhance perennial flower performance. Understanding some of the common terminology may be helpful.

WHAT IS DEADHEADING?

No, it has nothing to do with Jerry Garcia!Deadheading is the removal of spent flowers to prolong bloom, promote re-bloom , improve aesthetics or to prevent seeding.

Bloom sequencing- Cutting back a plant to delay flowering.Cutting back- Pruning back foliage and perhaps flower buds and deadheads to renew a plant’s appearance and/or to encourage new growth and flowering. Cutting back can also be used to control eventual plant height and/or flowering time.Pinching-Removing the growing tip and first set of leaves to promote the development of side shoots. Used to promote fuller, stockier plants perhaps. Thinning- Removing shoots, leaves or stems to open the plant canopy allowing for better air circulation

PERENNIALS THAT MAY REBLOOM WITH PROPER PRUNING

Achillea, Aster frikarti ‘Monch’, Astrantia, Campanula, Coreopsis, Delphinium, Dianthus, Dicentra formosa, Digitalis, Echinacea, Echinops, Gallardia, Gaura, Geum, Helenum, Heliopsis, Penstemon, Phlox maculata, Platycodon, Nepeta, Salvia nemorosa, Scabiosa, Stokesia, Tradescantia, Viola.

Be sure to select cultivars that readily re-bloom.

‘Carradonna’ and ‘May Night’ are better re-blooming Salvia varieties.

MAY-JUNE ZENITH OF BLOOM JULY GETTING TIRED

AUGUST RE-BLOOM

PERENNIALS TO PRUNE FOR IMPROVED FOLIAGE/OVERALL APPEARANCE

Achillea, Alcea, Alchemilla, Anemone, Arabis, Armeria, Artemesia, Aruncus, Bergenia, Brunnera, Campanula, Chrysogonum, Coreopsis, Delphinium, Dianthus, Dicentra, Echinacea, Echinops, Geranium, Helenum, Heliopsis, Helleborus, Hemerocallis, Heuchera, Hosta, Iris (bearded), Kniphofia, Leucanthemum, Monarda, Nepeta, Peony, Penstemon, Phlox, Physostegia, Polemonium, Pulmonaria, Salvia, Scabiosa, Stachys, Tradescantia, Veronica, Viola.

When in doubt… if it looks bad cut it off!

BEFORE AFTER

BEFOREDURING

AFTER

PERENNIALS TO TRIM FOR HEIGHT CONTROL/SHAPE/BLOOM SEQUENCING

Achillea, Aconitum, Adenophora, Alcea, Artemesia, Aster, Boltonia, Echinacea, Eupatorium, Gaura, Helenum, Helianthemum, Heliopsis, Hibiscus, Lavender, Lobelia, Lychnis, Monarda, Perovskia, Phlox, Physostegia, Platycodon, Rudbeckia, Sedum Autumn Joy, Solidago, Tradescantia, Veronica.

*Trimming may delay flowering.*Timing greatly affects eventual outcome.

16540 CHILLICOTHE RD CHAGRIN FALLS, OH. 44023 440-543-5123 WWW.LOWESGREENHOUSE.COM

Now go outside and have fun in the dirt.Thank you!