Ivy (Hedera) can be a wonderful plant: evergreen, fast to grow, many coloured and with the ability to clamber over a multitude of sins. It can also provide insulation and a natural habitat for birds and animals in your garden, but at what price to your walls?
While cutting back ivy covering a wall, damage done to the bricks, hitherto unnoticed, was revealed.
The top layer of bricks has been lifted off most of the wall
and the roots have burrowed into the mortar in large sections too.
Damage done will have to be repaired now to avoid a more costly intervention a few years down the road.
Speaking to the Brick Development Association (yes, I really did), they would warn against planting Ivy against walls, because, as seen above, the roots do infiltrate the mortar. They say the problem with Ivy, is when you want to remove it, as is so entangled that it will inevitably damage the wall. If you do want to remove it, they recommend cutting it at the roots and leaving it to die back for TWO YEARS! , before carefully removing the plant from the wall. As a gardener, I wouldn’t like to see a dead or dying plant in a garden for this length of time.
However the better shape the mortar is in to begin with, the easier to control the Ivy with regular pruning and possibly cutting Ivy right down to the ground every few years. Quite a task and obviously cutting right back would leave a bare wall for a good few months until the Ivy grew back again. Not ideal.
An alternative to Ivy, if you have a south or west facing wall and if it is sheltered and in a mild climate, may well be Trachelospermum jasminoides (Star Jasmin). It too provides evergreen coverage of large areas, with the added bonus of wonderful scent from mid to late summer.
Or a magnificent Wisteria if you have a south-facing wall. Not evergreen, but in winter you still have a very beautiful sculptural framework to look at. Worth considering, although it would take many years to achieve this marvellous growth above!