Experts and BHG readers answer.
Help for my wisteria!!!
Thanks for writing. Wisteria, especially plants grown from seed, are notiorious for taking a long time to bloom. If it's a question of maturity, I'm really sorry, but all I can say is try to have patience.
In the meantime, do be sure your wisteria is in full sun (shade can prevent it from blooming) and is in well-drained soil. Don't be afraid to let it be on the dry side as moist, rich soil can encourage lots of rampant leafy growth at the expense of flowers. Get pruning tips here: http://ohioline.osu.edu/hyg-fact/1000/1246.html
---Justin, Senior Garden Editor, BHG.com