Two years ago, when I started transforming my garden to make it better for wildlife, I planted Hedera helix (common ivy) along the base of the north-facing fence. It hasn’t grown much yet but I have visions of lush green walls alive with nesting birds, buzzing bees, flies and countless other insects, and of not being able to see the edges of the garden.
It will probably take five years before the fences are covered; another 10 before the ivy flowers. Still, the wait will be worth it. Because ivy is amazing.
Yet it’s almost universally hated by gardeners and homeowners alike. A self-clinging climber with a voracious growth habit once established, its reputation for damaging walls and fences is unparalleled. I’ve lost count of the number of times I’ve been told how awful ivy is, how it’s nothing but trouble and will destroy my house and fences.
How it’s an ugly weed, how it strangles trees, how it’s full of spiders, how it will form an easy-access ladder for burglars to climb into my home (really). It’s an ivy horror show out there. I’m amazed we allow it to grow anywhere at all.
Ivy is amazing. As a wildlife gardener, I couldn’t be without ivy as it’s used by so many species. On fences and walls it provides nesting habitats for birds and general shelter for anything else, including hibernating butterflies, pupating hoverflies and, yes – I won’t lie to you – spiders. Its autumn flowers provide a late source of nectar and pollen for pollinators – you can often hear the buzz of insects on ivy before you see it.
Its berries provide sustenance for birds right at the end of winter, when they need to get into shape for breeding. Its leaves are eaten by the caterpillars of the holly blue butterfly and moths including the double-striped pug and willow beauty. It’s versatile: grown vertically, ivy takes up little space and helps blend your garden with its surroundings. Grown as ground cover it suppresses weeds or bare soil where little else grows.
You can keep ivy closely trimmed so it looks lush and glossy or let it mature so it flowers and fruits. It’s easy to propagate and it’s cheap as chips.
And yet. It’s not just wildlife that benefits from ivy. More and more about this incredible climber is uncovered all the time.
A decade ago, scientists at Oxford University concluded that ivy actually protects buildings rather than damages them. That a thick layer of ivy leaves acts as a “thermal shield” on houses, insulating brickwork from temperature extremes and moisture that can cause cracks. Plant ivy against an already cracked wall and its adventitious roots will find them and cause problems.
But plant ivy against a good, sturdy wall and the wall will live longer as a result. Other studies show ivy reduces air pollution, with one Birmingham trial proving that metal trellises of ivy planted along a main road absorbed polluting particulates that might otherwise exacerbate asthma and other breathing difficulties.
And now a joint study conducted by the RHS and the University of Reading has shown that ivy is “the most effective plant cover for cooling buildings during hot months”.
Looking at climbing plants to assess how effective they were at cooling buildings in summer, the study found that ivy is not only the best plant for reducing internal building temperatures in summer but also reduces humidity throughout the year, presumably making conditions more comfortable in summer and less likely to cause damp issues in winter.
In the fight against climate change, polluted cities and the loss of biodiversity, we should be planting more ivy, letting it cover our fences, houses, even blocks of flats. Imagine how green, clean, cool and buzzing our towns and cities would be, how nicer our lives would be, if we just grew ivy. Spread the word: ivy is amazing.