Q: Last week you discussed controlling English ivy. But I have ivy growing up my house and I rather like the way it looks. It gives me shade and privacy. Is this a bad thing? Will it hurt the house?
A: I think it’s a bad idea to let ivy climb a wall. On a wall the ivy provides cover for insects, and sometimes animals, which can invade the house. The evergreen leaves shade the wall, but they also trap moisture, which can lead to mildew, rot or brick deterioration. The creeping vine tips can grow under wood and vinyl siding and loosen it. They have been known to grow through the insulation and come inside from behind an interior baseboard!
A better idea might be to erect a series of trellises at intervals down your home’s exterior and train evergreen vines to climb them. You could transplant an established clump of ivy to the base of the trellis and thread the vines up the framework. Evergreen clematis, ^Clematis armondii^ and crossvine, ^Bignonia capreolata^ are also good vines for trellising.