On Saturday 29th February 2020 I attended ‘On the Verge of Success. The importance for wildlife of our Roadside Verges’ with about 200 others, 9 speakers & many informative stands.
Firstly to point out what excellent organisation from the Suffolk Naturalists’ Society http://www.sns.org.uk/ and Wherstead Park http://whersteadpark.co.uk/ (who made feeding and watering 200 or so people seem effortless so we could concentrate on speakers and stands).
And secondly – it was a very detailed and fascinating day (which also involved not-plants) so these brief notes are what interested me and are not intending to reflect the whole of the day.
Design of new verges
- Soil fertility is key to biodiversity – low fertility gives high biodiversity coupled with low maintenance costs, because plants don’t grow as much. Any new landscaping specification/design for road verges should use mineral soil or subsoil & no topsoil.
- Spread local green hay & hand-collected seeds and accept it will take time to reach the equivalent of a species-rich grassland and acknowledge that the successional stages will be of high wildlife value too. Manage expectations.
- Don’t create a fast road with narrow verges (splat) or with narrow steep sides (funnel splat). In the Q&A splat of insects on cars was discussed: wider the verge the better and it was thought the level of splat would be below the benefit of increasing biodiversity. Also use as lever to improve/connect surrounding countryside.
Improving existing verges
- Three cut-and-remove targeted in one year makes a big difference with nutrient removal which can be seen in slower and lower grass growth the next year (small ride-on machinery is available to do this & Dorset County Council has just ordered more because it works for them financially esp. for urban areas).
- Can do the above and then scatter common grassland species seed e.g. oxeye daisy to create a more biodiverse sward. Also mentioned was a late cut in spring can give a shorter flowering height in summer (ref. horticulture’s ‘Chelsea Chop’)
- An example shown of turf removal (rolled and placed in hedge base) of a verge and resulting bare soil sown with green hay to give more diverse verge.
Maintenance cutting of verges
- The key here seemed to be if a road verge is a designated Roadside Nature Reserve (RNR) then it should be managed for the reason of designation i.e. a specific plant species/plant community/insect/fungus
- Otherwise variation in heights and timing of cutting throughout the whole of the area being cut, with cut material best removed. Plantlife have comprehensive guides https://plantlife.love-wildflowers.org.uk/roadvergecampaign Even regularly cut species-rich verge can be part of that mix, as can irregularly cut scrubby patches and uncut grass. [Apparently, Dormice live happily on scrubby shrubby road verges in some areas of the country.]
- Over-riding principle of road verge management is always the safety of road users.
- Who owns what and who is responsible for maintenance is not always who you might think.
- There is (usually) not enough money to manage Roadside Nature Reserves (RNR) without the help of volunteers, despite RNR extent being tiny compared to rest of roadverge network.
I was struck by the knowledge and experience that was available nationally for creation/management of bio-diverse road verges and left feeling enormously frustrated that this is all still at the pioneer stage in practice nationally and not really happening in my patch yet.
Who teaches the people who specify the soft landscaping for new roads and why do they choose to get it wrong every time? (in fairness I should add that Leonardo Gubert from Highways England gave examples of three roads in planning that are going to use green hay, but still, it really should be the norm and not the exception).
And why do the politicians (local and national) always prefer the expensive-to-maintain low-biodiversity option of sowing grass on topsoil and adding trees in plastic protectors?
Something for me to find out locally…