dr phil sterling - naturescot...dr phil sterling an ecological approach to amenity grass management...

Are we stuck with mowing amenity grasslands forever?

Dr Phil Sterling

An ecological approach to amenity grass management

• If we can control the amount grass grows in the first place,

we will have less to cut

• If we have less to cut, mowing should cost us less, and we

can spend more time on other jobs, and

• There will be more biodiversity because more species thrive

in poorer soils

• Response to austerity; ‘Climate Emergency’; C-reduction

targets; topsoil conservation; response to public awareness

Can we control the factors that make grass grow?

Rainfall – no control Sunshine – no control

Temperature

– no control

Soil fertility –

we can control

What does soil fertility do to grassland?

Thick topsoil – coarse grasses dominate – high fertility – few gaps for germination

Thin topsoil / no topsoil – fine grasses & herbs – low fertility – plenty gaps for germination

Happy coincidence

Our best grasslands for wildflowers, bees and butterflies develop on the poorest soils Lots of plants are able to compete for what nutrients are available Coarse grasses can’t dominate

Construction: Weymouth Relief Road, Dorset 2009 – 2011

Low fertility verges designed in 15mm topsoil or no topsoil Wildflower seed hand sown

2013

2019

Grassland management - 2 systems

Mow & leave arisings – lots of coarse grasses, few wildflowers

Cut & collect – fine grasses, lots of wildflowers

The Grillo: ideal for cut-and-collect in urban areas

Grillo FD2200 (Hydrostatic Out-front Mower)

3 x cut & collect in 2017 reduces coarse grasses and favours fine grasses - this is mid-May in 2018

Establishing wildflowers in amenity grass - reduce fertility first

Disposal on site

Disposal out of town on highway land, hidden in the bramble thickets

People now see common wildflowers on urban grasslands on their way to work or the shops. These wildflowers support insects such as common butterflies and bumblebees. Previously this verge was mown 5 times a year and supported almost no wildlife at all

Once regularly mown amenity grass, cut-and-collect started 2017, seeded in autumn 2017, now wildflower meadow in 2019

Typical urban verge in Blandford after 2 years cut/collect

A354 Blandford Bypass verges County Wildlife Site after 5 years cut-and-collect

Let your community know what’s happening

North Dorset verges cut by DCC staff – just 2x in 2018

The annual budget for highway verge management at Dorset Council is reducing year-on-year based on adoption of an ecological approach

Taking an ecological approach - conclusions

• If we reduce the amount grass grows in the first place

there’s less to cut, and

• We mirror natural conditions for flower-rich grasslands

• Low fertility can be achieved by design & management

• Saves money / staff can be redeployed more usefully

• The ecological approach will deliver a buzz in our towns &

cities on any amenity grassland at any scale