Ecological benefits / drawbacks of leaving grass to grow longer                                                          

 

Proposal

Pros

Cons

Comment

Reducing grass cutting to 6 cuts per year (highways verges and housing land)

 

Less disruption to insect communities. May give shorter plants like clover an opportunity to flower and seed, increasing diversity.

None perceived

A reduction in cutting frequency will still control more vigorous species. Creating a range of grass lengths will have the biggest benefit for biodiversity. The habitat for many of UK wildflowers is maintained in a natural landscape by wild grazing animals.

See Plantlife guidance on ‘Short grass and flowering lawns’.

Trialling a cut and collect once a year at some pilot sites (some verges like Hull Road central reservation)

 

Collecting the grass clippings reduces the soil fertility, resulting in lower growth rates, longer periods between cutting and a far better environment for wildflowers to establish, thrive and provide benefits to pollinators.

Collecting requires specialist equipment or can be labour intensive, both with cost implications

See Plantlife guidance on ‘Mid length grass and meadows’.

Leaving roundabouts to grow and only cutting a braid around the directional signs

Good for wildlife

Woody vegetation may eventually dominate and require extensive work to keep sight lines clear

See Plantlife guidance on ‘Year-round longer grass areas’.

More sustainable planting

 

More likely to provide prolonged habitat and food source for wildlife

Non perceived

 

Proposal

Pros

Cons

Comment

Bar Walls currently cut twice per year. Would you support a move to one cut or one cut on the outer and two in the inner

 

Either option is suitable on the proviso cuttings are removed from site

If cuttings are left uncollected the nutrient levels will increase, dominant grass and ‘weed’ species (nettles, dock, thistle) will establish and require more intensive management.

 

If two cuts, make first cut in late March, second in September.

 

If it is envisaged the cuttings can’t be collected it is better to leave the grass uncut.

 

Trialling of Schemes:

 

Our native species have evolved in a wild and varied landscape. To support as many of them as possible we need to replicate this diversity where we can. This means there’s no one ‘best’ way of managing the council’s grassland for wildlife – using a diversity of maintenance methods will maximise the number of species our grasslands can support.  

 

We are proposing 'cut and collect' mowing for the verge in certain areas – this is where we collect the vegetation clippings instead of letting them decompose into the soil. Collecting the grass clippings reduces the soil fertility, resulting in lower growth rates, longer periods between cutting and a far better environment for wildflowers to establish and thrive. This reduction in verge cutting allows wildflowers the time to complete their life cycles which benefits bees and other pollinators.

 

The key factor required for wildflowers is maintaining low soil nutrients (i.e. low levels of phosphates and nitrogen), this is usually the opposite to domestic gardens where fertile soils favour lush green grass, and fast-growing plants that would out-compete the delicate wildflowers. The seed produced by wildflowers would struggle to establish in nutrient rich soil conditions.

 

For further reading, please see well-established verge wildflower projects: 

Lincolnshire's Road Verges | Lincolnshire Wildlife Trust (lincstrust.org.uk)

Verge cutting information and maintenance standards in Dorset - Dorset Council