How and When to Prune Wisteria
In order to get a show of flowers every year you need to know how to prune and care for their needs to give them the best chance of resistance. As a gardener and designer, many people have asked for my advice on how and when to prune a Wisteria.
Wisteria has always been known for its lush growth and long spurs of leaves which shoot out to tangle and secure themselves to anything that might be unfortunate enough to be in its way. If kept in shape it will keep its structure very well.
Tie in all of the major stems as these will get heavy enough to fall and destroy the plant or cause the wisteria problems down the line. A common method used to keep the framework tie to the wall is a metal wire threaded through some tubing or sections of hose pipe, supporting the main stems and tied to the wall leaving enough room behind.
The long trailing stems that have weaves themselves through the frame of the plant or hang outside are to be cut back to within four to five buds from the main stem. This will leave a short prong coming from the main stem with four or five buds that will swell and turn to flowers around mid summer. If done correctly, the wisteria will flower across the whole plant covering it in dangling panicles of purple, lilac and white flowers. It's a stunning site when a Wisteria is a backdrop to a lower bed with flowers that compliment it completely.
A Wisteria should be cut back once in July when the flowers have finished and once in January when the foliage has fallen and you can see the whole framework without anything getting in the way. If the whole plant needs renovating, you can carry this out most of the year.
Make sure to cut the long spurs back to three to four or even five buds from the main stem and untangle and cut anything that doesn't fit in with the whole shape of the plant. When you're finished you'll know as it will look cleaner and healthier and ready for the huge display of flowers next summer!
To look after your plant a regular feeding from spring through summer will really help it to keep its strong growth and resist pest.
If it's a new plant that is to be planted, you need to make sure you prepare the planting hole as carefully as possible as this could easily live there for a good hundred or so years.
Dig the hole, line it with compost and sit it on a mycorrhizal fungi root building powder that you can buy in a pack. This is a naturally found fungi that will give the plant a second root system in as little as a few weeks. This being used commercially is relatively new but has had incredible results in wisteria and just about every other shrub so is fast becoming a standard process for planting.