Wisteria is such a classic climber, the essence of an English early summer garden. Laden with pendulous blooms in May and into June, these plants add beauty, colour, scent and a little natural wildness to any garden. Often they can have a second flush from July into August too, but this is less dramatic as they are already in leaf.
However, it’s well known that wisteria can sometimes take years to flower, and often don’t perform well even when they’re mature. Their vigourous nature (in the wild they climb up into trees and drip down like vines) means they can start to take over, twining their way up TV aerials, climbing into roof spaces and into the neighbours’ gardens. So it pays to establish an effective pruning routine to keep them in check and ensure you benefit from the maximum blooms next spring.
Ideally we want to ensure that vigourous growth is be re-routed into producing flower buds, not masses of trailing shoots, so the regime we recommend is pruning twice a year.
Summer pruning should be done now, in July or August, to tame those trailing shoots, and keep the shape of the plant looking tidier. Anything new and whippy should be cut back to about 6 leaves after the second flush, if you have one. This ensures it’s not going to climb into windows and generally make a nuisance of itself, whilst also concentrating energy on bud production in the autumn and winter.
Winter pruning is done in January or February. At this time of the year the plant is dormant and so it’s easier to see what you’re doing, as the leaves will have dropped off in the autumn. Take the shoots you cut in the summer back further to just 2 or 3 buds to encourage flowering. Doing this will ensure you get the maximum number of blooms, directing the plant’s energy away from leaves and stem growth.
When to start your pruning regime
Even if you’ve only recently planted a new wisteria, it’s not too soon to start your pruning regime. A light prune in the early years even if it’s not quite ready to flower yet will help to start getting your wisteria into shape, forming a strong skeleton for future growth.
A more established wisteria may need less formative pruning, but hard pruning in certain places to eliminate any dead or unwanted branches can be necessary to clear the unwanted limbs and promote strong growth. New shoots can then be trained to replace any that you’ve removed.
If you need any help or advice with pruning your wisteria get in touch with Chiltern Garden Design on the number above.
Choosing a new wisteria
When choosing a new wisteria to plant in your garden, make sure you’re buying a mature enough specimen so it will flower that year. Some juvenile plants available in garden centres and nurseries may take a decade or more before they flower, so it’s worth visiting in flowering season so select one with the type of blooms you like, and to ensure it will flower straight away.
Some of our favourite wisteria varieties:
Wisteria floribunda ‘Alba’ – a beautiful pure white variety with very long blooms
Wisteria sinensis ‘Black Dragon’ – a dramatically dark flower
Wisteria sinensis ‘Prolific’ – a classic lilac coloured lavender with, as it says on the tin, very prolific blooms