You may have noticed a lot of thrushes about this winter, and possibly even a few waxwings. These winter visitors from the continent love eating berries in trees, shrubs and of course hedges. With its flashes of yellow, white and red the waxwing is one of those birds that you will on occasion see in hawthorn hedges, and of course in spring the hawthorn hedge is a great resource for our pollinators.
The loss of many farmland hedgerows shortly after the Second World War was disastrous for pollinating insects in our rural landscape. Flowering hedgerows are excellent for food, shelter and nesting sites, as well as providing a safe and convenient corridor for ease of movement. Rural communities lamented the loss of the flowers which were a distinctive and much-loved element of fruit-bearing hedgerows. Perhaps less visibly obvious was that insects, birds and small mammals were denied a vital food source and home.
Today hedgerows are increasingly valued for their biodiversity benefits and the planting of new hedgerows is encouraged. But just as ‘Rome wasn’t built in a day’ neither is replacing hedgerows an overnight job.
It isn’t just the loss or rural hedgerows that should be of concern. The loss of hedges in our towns and cities is an issue too. And given that domestic gardens represent somewhere in the region of 20% of our townscapes there is good reason to fight the corner for hedges over fences.
We can be pretty confident that urban hedgerows (big or small) in domestic gardens contribute positively to the benefit of nature in towns and cities. At their most basic they provide nesting, shelter and travel corridors. When you add in the fact that they help remove particulates from the atmosphere then the case for hedges is increasingly strong.
A mixed hedgerow, with a variety of trees and shrubs, can have value through the entire life-cycle of pollinators. Blackthorn for example flowers early in the year – just in time to provide a vital food source for emerging bumblebee queens, solitary bees and honey bees. Farms with hedgerows help pollinators and enjoy many other benefits.
Hedges provide shelter for livestock (in both cold and extremely hot weather), , , increase the potential for carbon capture and storage in woody biomass, improve water infiltration rates to soil, reduce the potential for flooding and create wildlife corridors across farms. They provide habitat for essential wildlife, including beneficial insects and pollinators. As we increasingly look for Integrated Pest Management solutions pollinating insects provide natural pest control.
We know that pollinators, be they in a rural or an urban setting, need good food sources from early spring to autumn, in order to complete their life-cycles.
Flowering hedges that contain pussy willow, hawthorn and blackthorn are great for those insects on the wing early in the year, whilst come April and May hawthorn and wild cherry can be superb food sources for pollinators. Add to the mix dog rose, guelder rose and hazel and the potential for a hedgerow to be an all-year larder is clear.
It isn’t just the flowering of hedgerow plants that is important. At the base of hedges in amongst the tussocky grass, or vacated mammal holes, bumblebees might nest. Bare earth under a hedge (especially if south-facing), might also provide potential nesting sites for solitary mining bees. A range of pollinators from beetles to moths and butterflies will also find those sites useful for overwintering.
In short hedges can be havens for pollinators
Managing hedgerows to benefit pollinators
Key to hedgerows being a bonus for pollinating insects is allowing them to flower. Many hedges only really flower on wood that is at least a couple of years old.
As well as planting or managing a range of native flowering shrubs it is important to rotate how often and when hedges are cut. This will reduce costs and be better for wildlife. Many varieties of tree and shrub species only flower on second year growth, hawthorn and blackthorn, for example, benefit from not being cut every year.
Allowing hedgerows to flower, by moving away from the model of a tidy, short hedge, towards managing one which isn’t flailed annually is one very positive action that farmers can take. Trimming hedges every two or three years instead of annually or rotating areas trimmed increases the flower and fruit crop. Cutting hedges when in receipt of basic payment scheme support is not permitted between 1 March and 31 August under cross-compliance rules, to prevent damage to nesting birds.
Plugging gaps in hedgerows with native flowering shrubs keeps a wildlife corridor intact and leaving the occasional tree to grow above the rest of the hedge will add diversity. A recent survey of Scottish native wild apple trees found a number associated with field margins.
Consider cultivating flower-rich strips next to hedges. Flowers such as knapweed, clovers and vetches are great for pollinators.
Aim to cut hedges in rotation, across the farm and aim for an ‘A’ shape, where the densest area is at the base. This will encourage the hedge to thicken up and provide valuable shelter beneath the hedgerow.
By managing a hedge to help pollinating insects you benefit insects, birds and mammals as well as encouraging pollinators onto your farm. Further information on all aspects of hedge management can be found on the Hedgelink website.
Further reading:
The RHS have a guide that talks about hedges in some detail @ https://www.rhs.org.uk/science/pdf/climate-and-sustainability/hedges-for-environmental-benefits.pdf
The RSPB also have an excellent resource which explores the natural shelter that hedges provide and offers advice on selection and maintenance of hedges.
The OPAL website has a lovely article looking at some of the facts and folklore behind hedges. It also has various excellent resources to help with identification and plant association –
https://beewatch.abdn.ac.uk/xpolli-bumblebee/index.php?r=species/index
https://www.opalexplorenature.org/xpollination
Scottish pollinators 