Pruning Wisteria is not essential where they have room to roam and grow around a trellis frame. However, planted in a confined space, Wisteria will need some guidance on how it should grow.
You can prune your plant by removing any dead or diseased wood from branches that come into contact with ground level vegetation which could spread disease among other plants growing nearby. You also want to remove all its suckers because this will give more space for air circulation around foliage making them less susceptible to diseases such as anthracnose fungus growths caused by wet soil conditions.
Wisteria vines are strong and will soon become a tangled mess if left to their own growing habits. As we tend to grow Wisterias as ornamental plants, its best they’re kept under control.
To keep them in check, we should prune them twice each year. Pruning like this ensures maximum flower production while also keeping your vine growing within a set boundary.
When to Prune Wisterias
Autumn Pruning of Wisterias
Wisterias need to be pruned twice a year to keep them from becoming unruly. The first time should occur during the autumn, when it is best for you to trim back all of its current side-shoot growths and leaf buds so that they are 30 – 40 centimetres away from the main lateral branches by cutting at an angle on either side of each branch.
This will leave 4 – 6 leaves / leaf buds per shoot which can provide more warmth over winter months as well as give new shoots space needed ready for rapid summer growth without being crowded out with too many competing stems.
The second optimal is in early spring before any significant height has been reached.
Winter – Early Spring – How to Prune Wisteria
Prune your wisteria in January – February. Cut back side shoots 6-10 cm long, leaving only 2 or 3 buds on the shoot. There is no need to prune it toward an outward facing bud.
This will allow flowers buds – which are on older wood and closer into main stem – to receive food reserves surging up through the vine. If left un-pruned, they will develop into an untidy mess while depriving flower bud from even more growth by sending nutrients upwards through shoots and encouraging stem growth.
Wisterias require a tidying up in autumn, followed by hard pruning in late winter.
The optimum time for the autumn prune is October when most leaves have dropped off already from their branches on the ground below them. In February or early March before buds are fully developed is the best time for the winter prune.
If you decide not to prune your wisteria, then over the years the flowers on the plant will become smaller – as their energy will be focussed on providing new stem growth. So, prune your Wisterias regularly to produce larger flowers.