A well pruned wisteria is a delight to see. Sadly, all too often, they’re left to become a tangled and congested mass, flowering only sparsely at the top of the plant.
But don’t worry, even the most chaotic of wisteria will respond to a consistent pruning regime and reward you with a mass of flowers. Pruning wisteria was one of my favourite jobs when working as a gardener and many a happy an hour was spent up tall ladders bringing order from chaos.
Where to Start
This time of year (June), and once the flowers have died back, is a good time to start. Your aim is to create a strong framework of main stems covered with flowering spurs – these are the short, nobbly stems with little buds/leaves on them.
- As with all pruning, start with the 3Ds – dead, diseased and damaged – and remove the offenders.
- Continue by cutting out the “snakes”, long, thin stems about as thick as a pencil. Work logically removing them bit by bit or leave in place once cut and, once the leaves have withered, you can easily see which need to be removed.
- At the same time you need to tackle what we refer to as the “whips”, the long, thin new side shoots. These should be cut back to 3 or 4 leaves from the old stem.
- As with all climbers, support will be necessary. Don’t use garden wire or soft tie, as this will damage the stems and, ultimately, be enveloped by the stem – and twine won’t last long enough and will need replacing. The best option we’ve found is Flexi-tie, which stretches as the plant grows. It can also be reused.
- Step back now and then to look at the overall structure you’re creating and identify strong shoots to fill gaps and stems in the wrong place that need to tied in elsewhere.
- In late winter or early spring, all the side shoots produced during the summer (the ones you have shortened to 3 or 4 leaves in the summer) need to be shortened to 2 or 3 buds. This encourages the plant to create a healthy spur system of flower buds close to the main stem, just where you want them.
- And mulch. Give the plant a good layer of mulch as they are prone to drying out – well rotted farmyard manure or similar – creating a ring donut around the base of the plant i.e. no mulch against the plant stem.
What you’ll need