On Sunday I watched a blackbird almost strip an ivy of its berries, gobbling each one whole in a few, satisfying gulps. Other berries such as hawthorn and rowan are long gone and, while we’ve had some sunshine recently, the ground is generally still too hard for blackbirds and other thrushes to find worms. Ivy berries are some of the last available sustenance for hungry birds before temperatures increase and other sources of food reappear.
English ivy (Hedera helix), a British native, is as much a part of our heritage and history as it is food for blackbirds. Early herbalists believed ivy berries could counteract the unwanted side-effects of alcohol consumption. In ancient Rome ivy was a symbol of intellectual achievement and ivy wreaths were used to crown winners of poetry and athletics contests. Europeans used an alepole or alestake, consisting of a branch covered in ivy leaves, to indicate premises where wine or ale was sold. In Greek mythology Dionysus, the god of the grape harvest, winemaking and wine, wears a crown of ivy on his head.
These days ivy is loved and hated in equal measure. On the one hand it is hailed as one of the best plants for wildlife. Its evergreen, waxy foliage provides shelter for birds to nest and insects to hibernate, and it also provides food for caterpillars of the holly blue butterfly and the double-striped pug, swallow-tailed and yellow-barred brindle moths. It flowers in autumn when very little else is in bloom – take a walk around mature ivy in autumn and you’ll hear it before you see it: the buzz of wasps, flies, hoverflies and bumblebees, plus the colourful flutter of the odd late-flying butterfly, are all testament to its popularity with pollinators. It even has its own bee – the ivy bee, Colletes hederae, feeds almost exclusively on its flowers.
Calorie-rich ivy berries are loved by birds, including the song thrush, mistle thrush, redwing, blackbird and blackcap. Although the berries appear in November, birds don’t tend to eat them until around now – shorter-lived berries such as rowan and hawthorn are eaten first, leaving the longer-lasting ivy berries until last. According to the RSPB, ivy berries contain nearly as many calories as Mars bars, gram for gram. Do the birds leave the best for last?
On the other hand, ivy is also blamed for the death of trees and the crumbling of walls, and is often cut back or killed for this reason. However a study, commissioned by English Heritage, proved ivy can actually protect walls. Professor Heather Viles, who conducted the research, told me ivy acts “as a thermal blanket, probably regulating moisture conditions and also absorbing pollutants”. She did concede that it will exploit pre-existing holes or cracks in walls, but won’t actually cause them. Neither does ivy cause the death of trees – it merely uses them as a frame up which to climb, although the extra weight in the canopy can increase the likelihood of trees falling in high winds.
As a wildlife gardener I love ivy. A blackbird “sowed” some ivy seeds in my garden a few years ago. I’m hoping its descendants return one day to gobble its berries whole in a few satisfying gulps. I like the idea of birds cultivating their own food in my garden.