A well-grown wisteria trained on a house or pergola looks great all year round, especially in late spring when in full bloom. When established, wisteria make strong growth and unless trained and pruned on a regular basis they can soon become a tangled mass of twisted stems. Ideally, they prefer a sunny position, such as a south or west-facing aspect. In this situation the shoots will ripen in the late summer sun to encourage flower buds for the following year.
When training a young plant, the long growths will need tying to a trellis or wires to form a permanent framework of branches. Excessive growth will need thinning and, where possible, as many branches as you can should be trained horizontally to promote flowers. After flowering in late spring the plant goes into growth mode and over the summer long, whippy stems will be produced. It’s these long growths that need pruning back at this time of the year to tidy up the plant and maintain the trained shape.
If it isn’t pruned, the plant will very quickly become overgrown. Although wisteria prefers a sunny spot, some plants have suffered in the hot and dry conditions this year. Where plants are looking stressed and the leaves are drying out, give the roots a good soak to keep it ticking over.
Any long new stems needed to extend the framework should be tied in to the trellis or wires to continue training the plant.
The remainder of this summer’s long new growths should be pruned back to approximately 5-7½cm (2-3in) to create short side stems (spurs). Check the old woody stems are securely fastened to the support with strong, permanent ties that aren’t cutting into the bark.
Check the old woody stems are securely fastened to the support with strong, permanent ties that aren’t cutting into the bark.
If the hot, dry weather stressed the plant and foliage is wilting, give the soil around the roots a good soaking.