I get lots of green leaves, but no flowers after four years. If you planted seedlings, they may not bloom for 10 or more years says UC master gardeners Janet Wickland and Ken Brown. For best results plant cutting-grown, budded or grafted vines. The suckers also will take ten years to bloom. To eliminate surprises, purchase a plant that is blooming to ensure that it is of blooming age and that it is the color you want.
Wisteria needs ample water, good drainage, proper pruning and training for bloom production.
If you prune, be sure to not cut out all of the spurs that produce next year's flowers. Root pruning is cutting vertically with a spade into the plant's root zone. The Garden Detective column is compiled with the help of master gardeners at the UC Cooperative Extension Service in Sacramento County. Send questions to The Garden Detective, California Life, P.O. Box 15779, Sacramento, CA 95852. Please include your name, address and a daytime telephone number.