Answer: A 7 year old wisteria should bloom, but I have heard stories of 20 year old plants refusing to bloom. Some authorities suggest root pruning, meaning slicing downward with a sharp spade close to the vine on one side to sever half of the roots and thus shock the plant into feeling threatened and stress it into blooming in an effort to produce seed and reproduce itself. Maybe, with a little luck, this will be year the vines finally bloom for you! Otherwise, there isn't a whole lot you can do. Patience is about all I can recommend.
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