Ivy is a unnerving plant. Like a great green wave it just keeps on coming. It doesn't take long to engulf exposed lengths of fence, or stretch out tendrils to conquer new ground. Severe pruning doesn't dishearten it. Give it an inch and it'll take a mile.
It is an aggressive dark presence looming on the edges of the garden, threatening to drown everything in its way. But in some ways those Gothic qualities give it an elegant grace that save it from simply being an annoying weed.
Conservation charities generally remove ivy from the old buildings they look after because it can be damaging to weak masonry, but during the Romantic period of the early 19th century a covering of ivy was thought to enhance the appeal of any ruined monastery or castle.
“Where legendary saints and martyrs on the ornamented panes once testified the zeal of the founder and the skill of the artist, the ivy flaunts and the daw builds her nest while to a fanciful eye Nature and Time seem proud of their triumph over the labour and ingenuity of man" William Gilpin 1818
Whatever you think about it, if you think it romantic or menacing, it is an important plant for wildlife. At least 70 insect species eat some part of it, it can be the main food source for autumn foraging bees, and then other things eat the insects and the berries the bees create.