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10 year old Wisteria fails to bloom in Rockwall, TX.


Topic:
Author: Jimmy Mills
Date: Wednesday - May 15, 2013
From: Rockwall, TX

QUESTION: I love wisteria. I had four (4) wisteria plants professionally planted at least ten (10) years ago. These wisteria plants have NEVER bloomed. Why not?

ANSWER:

The native Wisteria in Texas is Wisteria frutescens (American wisteria), and according to the USDA distribution map, it doesn’t natively occur in Rockwall county.  This link to the Missouri Botanical Garden has lots of information about this Wisteria, and has this to say about flowering; “Failure of vines to produce flowers may be attributable to a number of causes including death of flower buds in winter, too much shade, plants too young (especially seed grown ones), improper pruning or over fertilization.”

It could be that you have one of the Asian species of Wisteria; Chinese Wisteria (Wisteria sinensis ) or Japanese Wisteria (Wisteria floribunda ). These can take up to 15 years for flowers to appear.

This fact sheet from  Ohio State University Extension tells a lot about these plants.

Here’s some interesting information from Purdue University; “Since most gardeners are drawn to this plant for its blossoms, they are quite frustrated by the plant's notorious tendency to produce only vegetation. There are many potential explanations for this annoying problem, including the plant's immaturity, too much nitrogen, insufficient phosphorus, poor-quality plants and too much shade.
Asian wisterias need to reach a degree of maturity before they are able to produce flowers. In fact, in can take up to 15 years or more before the vines reach blooming stage.
Those who have succeeded in raising wisteria often recommend root pruning, applying superphosphate, rigorous pruning of the shoots and planting in full sun. Most important, you should start with good-quality plants that have been propagated from cuttings of plants known to flower while relatively young. If you know someone willing to share a great specimen, take cuttings of the stem tips in July.  Avoid planting seedling vines because the genetic variability of seed reproduction makes it impossible to predict their blooming habit.”
The invasive potential of Asian wisterias  is a concern in some southern states.

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