Answer: There are several possible answers to this; wisteria is known for being slow to come into bloom especially if it was started as a seedling rather than as a rooted cutting. It may take close to twenty years if it is a particularly shy specimen. Having said that, some additional possible reasons are lack of sunlight, over supply of nitrogen, and either improper pruning or late cold snaps which damage the flower buds. Occasionally a gardener will report that severe root pruning has encouraged a wisteria to bloom, but I am not quite convinced there is a cause and effect relationship -- I suspect the plant had matured sufficiently right about when the gardener's patience wore out! Maybe next year will be the one for your vine!
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