Why Isn’t My Wisteria Blooming?

I have a wisteria that drives me crazy! It is five years old and has never produced a flower. I have trimmed, fed, talked to and even sang for this seemingly ungrateful plant and still it refuses to bloom! Can you help?

I can understand your frustration. I have received many emails from gardeners in a similar situation. Unfortunately, sometimes it takes wisteria an inordinately long period to bloom. Plants grown from seed often have long ‘juvenile’ periods before their first bloom. To avoid this start with plants that have been grafted or started from a cutting. Improper pruning or pruning in the winter or spring will prevent blooms.

Now here is the good news – there are a few things that you can do to promote flower production.

The first thing you want to check is where you have your wisteria planted. Is it in sun or shade? Wisterias require full sun. The more sunshine you give them, the better they will perform.

Wisterias also appreciate a good feeding. In early spring apply superphosphate. Just follow the directions on the label and put it around the base of the plant. This is pure phosphorus, which is the element that helps plants produce lots of blooms and fruit.

And finally, keep all the small tendrils pruned back throughout the summer. This will take constant attention, but it is worth the effort.

As a last resort, root prune the plants by cutting the roots with a sharp shovel. Do this in late spring or early summer. Make cuts at three or four places, about twenty-four to thirty inches from the base of the plant.

Good luck. I hope this helps you see some flowers soon. Although frustrating at times, I have to say, there is nothing like a wisteria vine in full bloom. When it happens, I think you’ll feel it was worth the wait.