Ivy-clad buildings can be attractive and are especially useful in adding interest to a shady spot. However, the ability of ivy (Hedera) to self-cling and grow rapidly can make it nuisance, so control may be necessary.
What is it?
Ivy is a woody stemmed, self-clinging climber that can grow quickly to cover fences, walls and buildings. It is a cause for concern owing to its rapid pace of growth and worries about potential damage to the support structure.
Ivy is recognised by its dense, evergreen foliage. In its climbing state it has three- to five-lobed glossy leaves.
It attaches itself to supports by producing aerial roots along the stems. When the stems are pulled away from the wall, they often leave behind the unsightly root ends, that persist and can often only be removed with wire brushes or pressure washing.
Self-clinging climbers such as Boston ivy and Virginia creeper (Parthenocissus sp.) do not usually cause damage to wall surfaces, but common or English ivy (Hedera helix sp.) supports itself by aerial roots and where these penetrate cracks or joints they may cause structural damage. Sound masonry is unaffected.
Its dense cover can hide defects in the fabric of the building and hinder maintenance work. Ivy may also provide access for intruders and harbour pests such as mice.
Where brickwork is sound, the main problem is to keep growth away from gutters and paint work.
It has been suggested that vegetation attached to walls could lead to dampness resulting from slower drying conditions following rain. This may be plausible on a south-west facing wall where the rain is driven by prevailing winds. However, other sources suggest that such plants will have a slight drying effect on mortar and will also provide some degree of insulation in winter, particularly evergreen ivies covering exposed north and east-facing walls.
Large climbers can pose a risk to buildings. Such problems are most likely with older property, those with shallow foundations and those built on clay soils.
Where possible, use non-chemical methods. The stems should be cut back to the ground and the woody stump dug out.
If proximity to foundations prevents removal, regular cutting of the stems to ground level may weaken the ivy over time, but is unlikely to kill it.
- Ivy can be killed by severing the stem and treating the stump with a proprietary stump and rootkiller (e.g. Scotts Roundup Tree Stump & Rootkiller, Bayer Tree Stump Killer, Doff Tree Stump & Tough Weedkiller and William Sinclair Deep Root Ultra Tree Stump & Weedkiller)
- Top growth may be treated with Vitax SBK Brushwood Killer or glyphosate, but ivy is not easily controlled by weedkiller sprays due to the glossy nature of its leaves. Repeat application may be necessary. Once the foliage has been killed, it can be pulled from the wall
Dead foliage and stems are relatively easy to remove from walls but aerial roots are persistent and can only be removed using a hard brush or paint scraper.
Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see sections 1a and 4)
Chemicals: using a sprayer
Chemicals: using safely and effectively
Chemicals: using spot and broad-scale weedkillers
Common name Common ivy or English ivy
Botanical name Hedera helix
Areas affected Fences, walls and buildings
Main causes Woody climber with fast, dense growth
Timing Seen year round; treat accordingly