Anybody who’s grown wisteria knows that from late fall to spring, wisteria vines are leafless ropes. Not until April, just as you’re reaching for the hatchet, does wisteria start its sensational transformation. Clusters of scented, pea-shaped blooms, usually lilac to purple, less often pink and white, open gradually and dangle languidly from the vines.

There are fans of both the Chinese (W. sinensis) and the Japanese (W. floribunda) Wisteria, which are the two most commonly planted species, but whether you prefer the plump clusters of W. sinensis to the elongated cascade of W. floribunda blossoms, the overall effect of this plant in full bloom is breathtaking, especially if you appreciate wisteria’s somewhat musky scent. Besides the show of blooms, though, wisteria is noted for its masses of greenery, which start to grow as the blossoms open–fern-like, divided leaves that start out a shiny bronze, turn medium green as they open, then turn a soft butter yellow in autumn.

After wisteria’s flowering debut in spring, it turns from blossom princess into rapacious colonizer. Unchecked, its vigorous, twining streamers easily reach between 40 and 100 feet, which is fine if there’s an abandoned bus you want to decorate in the back yard. If not, wisteria should be pruned regularly, both to keep it in bounds and to promote better flowering. In summer, a couple of months after blooming, prune new growth back to just a couple of leaves short of the old (darker) woody stems. Also, prune away any growth from grafted plants that comes from the rootstock (below the graft).

A few things to bear in mind about wisteria seeds: first, they’re poisonous; second, they, the pods and leaves do create a bit of garden litter; and third, although fresh wisteria seed sprouts readily, vines grown from seed, as opposed to grafted plants, sometimes take upwards of seven to ten years to bloom.

This spring Berkeley Hort is offering grafted plants of Wisteria floribunda (Japanese Wisteria) and Wisteria sinensis (Chinese Wisteria).

Wisteria floribunda varieties

• ‘Anwen’
• ‘Black Dragon’
• ‘Hon Beni’
• ‘Issai Perfect’
• ‘Lawrence’
• ‘Longissima’
• ‘Longissima Alba’
• ‘Royal Purple’
• ‘Shiro Noda’
• ‘Violacea Plena’

Wisteria sinensis varieties

• ‘Amethyst’
• ‘Blue Sapphire’
• ‘Caroline’
• ‘Cookes Purple’
• ‘Southern Belle’
• ‘Texas White’

We will also have these less-common wisteria varieties: Wisteria venusta alba, with short, fat clusters of strongly scented flowers in late spring; Wisteria hybrid ‘Burford’ with Japanese and Chinese parents; and the less aggressive American native, Wisteria frutescens.

– Margaret