my wisteria vine is 11+ yrs old(bought it at reputable garden center-since lost tag)...i can't wrap my fingers around its trunk anymore, as trunk is larger than most of my ornamental trees. it has never bloomed! for the most part i'm keeping it contained in size no more than 6-8' from the main trunk. it would be a tree form now if i didn't have it so close to my garage.. last few years in mid summer(when i see again it has not bloomed)i prune it back -similar to climbing roses leaving 4-6 leaf buds on the laterals.3 yrs ago i root pruned with a spade about 1 1/2' from trunk and down about 1'., 2 yrs ago i tried high phosphurus fertilizer, ...tried everything the last few years---no blooms! same story-beautiful healthy foilage. i'm very discouraged...of course its too early to tell this year yet-but anyone have any ideas?