Boston Ivy Parthenocissus tricuspidata

Boston ivy is the vine on the red brick walls of older city buildings: a deciduous climber that goes straight up flat masonry with no support at all, then turns crimson, scarlet and wine purple in autumn before the leaves fall. It is not a true ivy. It belongs to the grape family, and its glossy, three lobed leaves look like small grape leaves. It climbs with short branched tendrils tipped with adhesive pads that glue themselves to brick, stone, concrete and render, which is both its great strength and the reason to think carefully about where it goes.

Summer shade on a wall, winter sun through it

Its most useful job is cooling a building. Grown over a west or north facing brick wall, the leaf cover shades the masonry through summer and keeps the rooms behind it cooler, then drops in autumn so the winter sun can warm the same wall. Where a wall needs cover in winter as well, the evergreen twiners in Climbing Plants do that job on a frame instead. It grows in full sun or part shade and will cover a south wall, though autumn colour is richest with sun and cold nights. Cool and temperate districts suit it: Melbourne, Adelaide, Canberra, the tablelands and Sydney. In the humid subtropics it grows but colours poorly, and it is not a plant for the tropics. Once established it handles dry spells and most soils, from clay to sandy loam, as long as the roots are not waterlogged.

What it does to a house

On sound face brick, stone or concrete the damage is mostly cosmetic: the pads sit on the surface, and unlike English ivy, an environmental weed in much of southern Australia, it sends no rootlets into the mortar. Treat any wall it covers as permanently marked, though. Left alone it climbs onto window frames, into gutters and under roof tiles and weatherboards, and over the years it can lift loose render and pull paint away. Once attached it is slow to remove cleanly: pulling the vine off leaves thousands of small pads stuck to the wall, which take a stiff brush and patience to scrub away. Keep it off timber cladding, painted surfaces you plan to repaint and walls with crumbling mortar. If you are still choosing between a self clinger and a twiner on a frame, read Climbing plants for fences, pergolas and screens before you commit a wall. Each summer trim it back from windows, doors, gutters and the roofline, and in autumn expect heavy leaf drop into gutters, drains and any pool nearby. The small blue black berries that follow the inconspicuous flowers are mildly toxic if eaten, so keep them away from children and dogs.

Getting it started, then keeping it in bounds

Expect little for the first year or so while the roots settle, then fast growth once it takes hold. Plant it close to the base of the wall with the stems leaning in against the surface; new shoots grip most readily on rough, clean masonry, and a few strips of tape can hold them in place for the first few weeks. Dig compost through the planting hole, water deeply through the first summer and mulch well. After that it asks for very little: water in long dry spells, and a slow release fertiliser in spring only if growth is weak. Prune in winter while it is bare and the framework is easy to see, and cut back hard at any time of year when it heads somewhere it should not. Powdery mildew and leaf spot can appear in still, humid corners but rarely do lasting damage. To cover the often dry strip of soil at the foot of the wall, plant a low, tough clump such as Blue Flax Lily, which copes with root competition and little water once established.

Choosing a size

This plant is supplied in one size, 300mm, at $229.00 per plant. The size shown is the pot it arrives in, which is the rootball, not the height of the plant. Not sure which to choose? Read our guide to low water gardens.