Shape shifting

Some trees can’t help growing out of control, but Toby has some tricks to keep those in small spaces in check

ON my way into town, I pass a rapidly growing blue cedar that’s planted in the tiny front garden of a Victorian terrace. It’s only been there a decade, yet it already looms like an arboricultural cuckoo over the garden path and worries the gutters.

It won’t be long before it smothers the neighbours or is felled, and is proof – if needed – that large trees and small gardens don’t mix. That said, there are techniques – perfected over centuries by Japanese gardeners – that can mini-me even a mighty blue cedar.

Bonsai is the most extreme and well-known method (see the panel), and works for both trees and climbers. There’s also cloud pruning, which is suited to medium-sized trees and shrubs, plus a ‘new kid on the block’ already being practised by forwardthinking nurseries here in the UK.

‘Multi-stemming’ is a pruning technique that creates smaller specimen trees that look much older (and are therefore more valuable) than those of a similar age left to their own devices. Just like us, trees change shape as they age – only more dramatically. Get your eye in, and you’ll notice that they develop from leafy pyramids when young into clear-trunked columns or domes as they mature.

Multi-stemming replicates this process, but from a young age. The main trunk is pruned to encourage a flush of new stems from the base. The bestplaced two-four of these are left to grow until they are about the thickness of a wrist, when all the lower branches and twigs that clutter the inside of the canopy are cut away with secateurs.

Rather than diminish, this ‘opening up’ so the trunks can be seen replicates the mature look of an established tree. The reduction of twiggy growth and the development of extra trunks also has the effect of reducing the vigour and therefore the eventual height of the tree by around a third. Perhaps

I’ll suggest one as a replacement for the blue cedar...

“Multi-stemming creates smaller specimen trees”

Multi-stemming creates smaller trees with the appearance of being much older, as with this Acer palmatum Bonsai is the most well-known method for making small versions of big trees as with this Satsuki azalea Cloud-pruning is effective with medium-sized trees like Pinus sylvestris ‘Watereri’