Hedges for Wildlife
Our native hedges are amazing. They’re one of the oldest man made features in the British landscape, they’re beautiful things and a fantastic resource for wildlife. Mixed hedges using native species are easy to recreate and manage, and I’m always surprised that more folk don’t go for them.
Why a Native Hedge?
Our native hedge plants seem to be a bizarrely under-utilized resource particularly in urban environments. Perhaps people associate them with unruly mixed hedges, when they want a clean and tidy look. In which case, why not use a clipped single species hedge? These plants can be as architectural as yew or box; we’re in the middle of designing a garden at Chelsea which will include cloud pruned Hawthorn - like Blackthorn, a great security barrier beautiful in spring and fruitful in autumn. For all year round interest add summer colour by including native Honeysuckle, Lonicera periclymenum, or Dog rose, Rosa canina. To my mind the more species in a hedge the better, improving interest and increasing its associated biodiversity. Structurally mixed hedges look more sound; a good mix of suckering species like Blackthorn and Hazel will continue to give them body.
Food - As with all our native plants, common hedge species have unique relationships with our native fauna. When thinking about food provided by hedges most people think about the berries for birds and small mammals – and larger mammals like us! There’s a largely unnoticed community of animals further down the foodchain depending on hedges for other forms of sustenance. Our butterflies and moths have unique relationships with our native plants. For example the Yellow Brimstone caterpillars feed exclusively on Buckthorn,
Brown Hairstreak has a similar relationship with Blackthorn. Think of the number of plants in a native hedge and you can imagine the volume of pollen and nectar even a short length will produce, as opposed to individual flowers. The mix of species also ensures a long flowering period – there’s rarely a time when something isn’t in bloom. From the Blackthorn blossom in early spring saving the honey bees from starving, to autumn-flowering ivy allowing them to stock up for winter on warm days. Different flowers attract different pollinators, thus a mixed native hedge supports a whole range.
Shelter and Movement - Plants like blackthorn and hawthorn provide fantastic shelter for invertebrates, small mammals and birds. Hedges are handy corridors for them too, offering relative safety for animals while they move about. One of the issues exercising the conservation lobby at the moment is the fragmented nature of biodiversity hotspots, which need to be joined up. Hedges can be a pretty good way to do it, at least on a small scale. They're not just used for access by wildlife, but also as navigation features. Bumblebees fly by them and bats use them to find their way across the landscape.
Starting a Hedge
Please use a British nursery for your plants - there are plentyonline. Some of the large scale hedge planting over the last 20 years has used plants from all over – Eastern and Western Europe. Plants have genetic variations as do animals, so it’s a good idea to use plants with British provenance. Some suppliers are either coy about provenance or infer it, so ask them directly. Traditionally you’ll need 5 plants per square metre to create a stockproof staggered double thickness hedge, but that’s not to say your hedge MUST look like that. You might not have enough room for two rows of plants, for example, although the thicker the hedge the better for wildlife.
Most woodland nurseries’ conservation hedge mix is a good diverse default mix and qualifies for any grant aided planting. Nurseries will usually tweak their standard mix to your requirements. Personally I’d recommend using 60-90cm plants; they’re still pretty small whips, which are easily planted and quick to establish. There is no point buying anything bigger as you’ll end up with a hedge with no base.
Although we’ve pretty much arrested the decline in the length of hedges in the UK, they’re beginning to turn into rows of small trees. Left unattended your hedge will go vertical, which is less helpful for all than a dense hedge with a wide base. You can prevent this by pruning the growing tip off your new whips encouraging lateral growth. As time goes on the ideal way to ensure a perfect hedge is to lay it, but that’s often not practical. Establish a trimming regime that impacts the least on local wildlife; the Single Payment scheme asks for hedge cutting to stop between 1st March and 31st July, but the optimum time to do it is January and February, after the berries have been eaten but before birds start nesting. Trim a hedge in a two or three year rotation to let it fill out. The Single Payment scheme quite sensibly specifies a 2m wide uncultivated zone from the middle of the hedge. If you do need to take extreme action to get a hedge back under control coppice it in sections, year by year, to minimize the impact on wildlife. Ideally, gap up a hedge while renovating it with locally sourced whips in keeping with the species you see around you.
Article by Nick Mann, Habitat Aid
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