When Does Wysteria Bloom?

Timing

• When purchasing a wisteria vine, look for one that is grafted. Vines grown from seeds take as long as 10 to 15 years to reach maturity and don’t bloom as juveniles. Even grafted varieties take six to seven years to bloom. Once the wisteria reaches maturity, if it’s cultural requirements are met, look for it to flower in spring.

Conditions

• Wisteria doesn’t bloom if it’s grown in the shade, so plant the vine in an area that receives at least six hours of sun per day. The vine flowers better when growing in somewhat acidic soil, with a pH between 6.0 and 7.0. When planting, place the graft union -- the bump on the lower part of the vine that indicates where it was grafted onto rootstock -- just below the surface of the soil.

Water & Fertilizer

• Water and fertilizer are necessary items for the young wisteria’s growth. The mature wisteria, on the other hand, blooms best when these items are withheld. Supply the newly planted wisteria vine with 1 inch of water every week if it doesn’t rain. Water the mature vine only when it wilts. Fertilize young vines until they reach the size you want then stop fertilizing, unless the vine isn’t growing properly. To encourage an older vine to bloom, give it 1 inch of sulfate of potash per square yard of soil in the wisteria bed. Scatter it around the base of the vine and water to a depth of 8 inches.

Pruning

• Pruning the wisteria should be an ongoing chore if you want your wisteria to bloom the following season. Prune out all of last season’s shoots in January. Cut them back until there are only three buds per stem. In July, prune it again, this time cutting it back to the size you desire. Mature wisteria vines that refuse to bloom may be encouraged to do so with root pruning. Cut through the roots 2 feet from the base of the vine, in a complete circle around it. Drive a shovel into the soil to sever the roots.