The period between the end of July and early August is really important if you’re lucky enough to have Wisteria in your garden. Personally I think Wisteria is among the most impressive and enigmatic flowering plants you can own. To coax them into their best flowering they need to be pruned twice each year and it’s now time for the first. Each Summer they produce long, thin ‘whippy’ green shoots that are usually several feet long. It’s these new green shoots that need to be pruned now and not the old, brown thickened branches formed in previous Summers. If the plant has been neglected for several years and has too much old wood on it it can be pruned though that’s a job best left until Winter! So, how do you ‘Summer Prune’ Wisteria? First, identify one of the new shoots and trace along it from the tip back to the point where it is attached to the old woody growth.
Now reverse direction and trace back along the shoot towards the tip and count five leaves. When you’ve located the fifth leaf cut the shoot just beyond it. In Winter you need to return to this severed shoot and cut it again. It will look rather different by then because the leaves will all have fallen off, buds will be visible where the leaves used to be attached and the shoots will have hardened and turned brown! You then re-cut the same shoot but this time just after the second bud. At this point you may be feeling rather confused. These seem like rather arbitrary and complicated instructions. Why does it need to be so complicated? The answer is that experience has shown that pruning the new shoots in this way causes physiological change within them which should convert them into structures called ‘spurs’. Spurs are more likely to produce the flowers in Spring that we prize so highly. Wisteria can take three or four years after planting in a garden to bear flowers for the first time. They require patience, the right conditions and persistent, disciplined pruning to perform at their best. When they do perform however few plants are as impressive or as rewarding.
