Vine Of The Times Perennial garden favourite, wisteria.
Is there a more romantic garden vision than wisteria in full flower? Helen Young reveals the secrets of everyone’s favourite bloom…
The abundant pendulous flower clusters of wisteria are one of the prettiest sights of spring, augmented by a sweet, creamy perfume. It’s best grown where you will walk underneath it – an arbour or pergola is ideal – to allow full appreciation of the blooms. As flowering finishes, the divided leaves burst forth and elongated seed pods can develop. The long tendrils grow rapidly during summer, then in autumn the leaves turn yellow before falling.
Vigorous and easy to grow, wisteria can be trained across the top of a verandah or grown as a weeping standard, but be aware that it needs a very strong support for the heavy stems and that its growth needs to be controlled. It climbs by twining around anything within reach. Left unchecked, it will romp up tall trees, smother nearby plants or even start growing through your roof! They’re very long-lived plants, and hard to kill, so plant wisely.
CARE
Wisteria thrives in cool climates but is adaptable to warmer areas outside the tropics. It is best in full sun with shelter from severe winds, and is not too fussy about soil as long as drainage is good. Install a strong support (metal in preference to timber) before you plant. One plant can cover a huge area, but if planting along a pergola, space them at intervals of about 3m. Train main stems straight up until they reach the top of your support, then train horizontally.
Once the framework is established, pruning is the main job. Cut back rampant tendrils during summer and/or prune in winter when it’s easier to see the stems. Wisterias flower on old wood, so you must leave three or four pairs of buds at the base of each stem that grew during the year.
These develop into the short spurs that bear flowers. Fertilise in early spring and again in early summer to promote growth. Apart from possums, which eat leaves and flower buds, wisteria is quite pest- and disease-free.
VARIETIES
Japanese wisteria ( W. floribunda) has slender flower clusters about 50cm long. The species has mauve flowers but there are variations: ‘Alba’ is white (pictured), ‘Rosea’ is pale lilac and ‘Violacea Plena’ has violet double blooms. ‘Macrobotrys’ has pale lilac flowers up to 90cm long. Japanese wisteria often produces long, furry seed pods (NB these pods are poisonous). Chinese wisteria
( W. sinensis) has thicker mauve flower clusters, about 30cm long. W. ‘Amethyst Falls’ is a smaller variety that needs less pruning, with short, deep lilac blooms than can repeat through summer. Silky wisteria ( W. brachybotrys ‘Shiro Kapitan’) has downy leaves and white, very fragrant blooms that are held slightly upright.