Now that the leaves are off deciduous trees, ivy is glaringly obvious, sometimes just covering the trunk, in other cases topping the whole with a ball of greenery. In one case a friend had to have the whole top removed from a tall hawthorn, which was crowned with a mass of creeper just outside the house. He reckoned that if a storm hit, it would all come down. And then you come across an article in a serious journal, The Countryman, which is headed "I Like Ivy".
The writer Pete Bryden argues that it "creates magnificent natural sculptures as it cascades from trees and clambers over our walls and hedgerows, helping to keep the countryside green and providing cover and food for wildlife". People tell him, he writes that ivy kills trees. The writer goes first to the Royal Horticultural Society, where the point is made that ivy is non-parasitic. The little rootlets that help it climb a tree have no other function. Ivy does take over rapidly in the case of a diseased tree. Most healthy crowns, however, will let insufficient light through for the ivy to grow vigorously. The Forestry Commission sent him a report summarised as "ivy may be unsightly and it can create problems for tree managers.
These adverse effects should be compared with its conservation benefits before destroying the climber". One of the most striking experiments was carried out in 1890. Ivy was cut on half the trees in a wood, and left to its own devices on the other half. By the 1930s, the uncut ivy "quite covered the trunks and main branches" but when the wood was felled in 1942 "no difference could be found in the height, average girth or cubic content of the trees."
Ivy on walls can be dicey, entering cracks in stone and brickwork and it should always be cut back from eaves, gutters and roofs. And any plant growth on a building could conceal defects that would otherwise be apparent. The General Secretary of the British Beekeepers Association said that ivy is the bees' main source of late pollen and nectar. And he reminded us not to forget how many birds find shelter and comfort in ivy. Pete Bryden has, over the last three years, had tree creepers, wrens, robins and thrushes nesting "in my heavily infested willows". Tawny owls and many other woodland birds, too, he says.
The flowers at their best make agreeable decorations, and wood-pigeons, starlings, and others feed on the berries. "Poisonous in large quantities". He pleads that ivy is "sometimes thought to be unsightly and is often persecuted". Indeed. "There are many environmental benefits that we should take into account before jumping in with the saw, and a regular programme of inspection and control should be the preferred approach". That's the trouble. Bare trees with a haystack of ivy on top not only look out of place but can be dangerous.