Live in Zone 6 My wisteria (now about 5 years old) has always bloomed- not well though. It is absolutely huge but again, not a whole lot of blooms. This year, it is even taking a while for the leaves to come out (still not completely full and it is June 9). I trimmed it back quite a bit in spring (probably about end of April). Any suggestions? I have fertilized it once - last week.