Wisterias can be as infuriating as they are beautiful. At their peak, their long colourful cascades of flowers can be stunning and almost everyone who sees one in its prime would like one for their garden. The problem? Well, 6m (20ft) is nothing for a wisteria so for many gardens they’re just far too big. Or are they?
There are two factors to consider that will help you grow your own wisteria: 1) Choose the right variety; 2) Prune it regularly.
Always buy a named variety. Unnamed plants may have been grown from seed and take fifteen years to flower – life’s too short. 14 varieties of wisteria have been awarded the Award of Garden Merit (AGM), and there are many more, so there’s plenty of choice in purple-blues, blues, pinks and white and many are fragrant - a few are even double.
Varieties of Wisteria sinensis have the benefit of flowering in May and June before the leaves develop and start to mask the display. ‘Prolific’ is outstanding, living up to its name with 30cm strings of bluish-violet flowers that all open together for the most dramatic effect. ‘Jako’ is a strongly-fragrant white, ‘Amethyst’ is reddish-violet; all are deal on a house wall.
The longest racemes of flowers belong to the fragrant lilac W. floribunda ‘Multijuga’, they can be 1m or more in length but the plant needs to be allowed to grow high to show them off. Scaling a huge ladder to prune is not everyone’s idea of gardening. I once saw ‘Multijuga’ allowed to scramble up, unpruned, a mature Lombardy poplar – that was a sight.
Also consider ‘Domino’, whose two-tone lilac-blue racemes are among the shortest, but appear on very young plants.
The largest individual flowers come with W. brachybotrys, although they come in short racemes, and the scent of many varieties is exceptional. The plants, however, are amongst the most vigorous. ‘Showa-beni’ is the best pink of all, ‘Murasaki-kapitan’ (photo below right) is an exceptionally fragrant violet-blue.
Finally, look out for two hybrids, both with two-tone violet flowers: ‘Burford’ (above left) has flowers in 45cm (18in) racemes, ‘Caroline’ has short racemes but is one of the earliest.
Pruning is necessary twice a year to promote flowering and to contain the plants in the space available. Follow the RHS pruning recommendations.
And there’s another approach: train your wisteria as a standard, it can even be grown in a large container. Those RHS pruning recommendations outline how to go about it.