Hello Master Gardener,
My Japanese Wisteria is approximately 7.5 feet tall.
It faces west, but the garden has south east exposure.
This is the second year producing seed pods. How can I prune and when. Also, are the seeds usable?
Sorry, tried uploading photo, size is too big
Thankyou for asking us about pruning your wisteria. It sounds very happy and vigorous .
Two pruning sessions per year are recommended for wisteria; late winter before buds and mid-summer after blooming While a few weeks ago in March ,would have been ideal for yours , given its strong growth habit , you could risk pruning now though you will lose some flower buds. It should not kill the plant and it is better to have your vine pruned for health even at the risk of some blooms. Next year, you can prune before the vine begins to grow for the year. Then after blooms drop , prune again .
Here is a link to an article by the British Royal Horticultural Society which explains the techniques to use for wisteria pruning. It mentions pruning in January or February but ignore that . Here, where our winters are longer, March is a good rule. https://www.rhs.org.uk/plants/wisteria/pruning-guide
Here also is a link to a video by an Ian Cooke that will give you confidence as he calmly demonstrates how to do it. https://youtu.be/jydSj7vnlVw and a link to the University of Utah’s simple explanation of pruning a wisteria. https://extension.usu.edu/yardandgarden/research/wisteria-in-the-garden
Do not let these overwhelm you ..the overall aim is to establish a framework of horizontal branches (which are more likely to flower than vertical branches) and promote flower bud formation (“spurs”) at controlled intervals. Choose your strongest vertical stem to serve as the main “leader” . Train side branches (laterals) at a 45-degree angle and about 18 inches (45 cm) apart to allow room for the blooms to dangle down without running into each other . Pinch off the main leader when it reaches the desired height. Do not allow suckers to sprout off the main leader or grow out at ground level.
You mention seed pods, which all legumes ( like peas and beans, wisteria is a legume) produce after flowering . If you want to try growing a new wisteria from seed, be prepared to wait for a bloom for as many as 15 years and even then , the bloom may not be true to the parent plant. You would have more satisfaction ,trying to propagate from a cutting .
Best of luck with your pruning project!
April 16 2023