Thanks for the fertilizer information. It got me wondering...I have wisteria vines that are 15+/- years old which have never bloomed. I’ve heard some varieties take many years before blooming. I was going to rip them out, but maybe I will apply some phosphorus and see what happpens. They’ve been there this long, what’s another year or two :)
Wisteria, unless you’re in the deep south, is very hard to get to bloom in the north. It’s got to be the late and/or early freezes, and sometimes both, messing with the bud set for the next season.
But, you’ll always hear the story of, “My neighbor...my sister...my cousin...has one that blooms every year and they never do anything to it...blah, blah, blah.”
The right plant for the right place. If a non-blooming wisteria is making shade for you and looking beautiful and green and leafy and healthy otherwise, I’d enjoy it for what it is; a non-blooming, shady-producing, sturdy, green vine. :)
Ah...the “wisteria” problem. LOL Yours is a common lament. This is going to be a long reply, but before ripping them out, try one more thing that may work.
Wisterias are pretty lazy plants. They’ll do the easy part (lush foliage) without blooming and won’t do the hard part (blooming) until forced to. Literally.
First off, deprive that lousy plant of nitrogen. That’ll teach her! But here’s the second part (and YES I do know it sounds insane). This is the proper time of year to do it, as it should have bloomed. I want you to whack the woody part of the plant with a baseball bat. (Now, make sure you take something like a washcloth and rubber band it around the thick part that is striking the plant.) The goal is NOT to damage the cambium layer, it’s to put stress on the plant. I want you to do this every day for 3 weeks to a month. About 4 whacks each day, all at once. After a month, stop. If your wisteria doesn’t bloom next spring after this treatment, you have my permission to pull that ornery plant out.
Why it can work? It “resets” the plant into a more normal cycle. Plants are at their most tempting in the nursury when they are in full bloom. But...in order to get them that way, they are usually grown in a climate foreign to your own. They can often seem to never get their act together, bloomwise. The “stress whacks” I mention simulate the plant being attacked by a dear or beaver, perhaps enough to kill the plant. Under those circumstances, a healthy plant will (at the proper time) release plant hormones that will enable it to survive...via SEED. Translation=no flower, no seed. heh The timing is designed to coincide with the normal time that they would do this in your area (i.e. as your neighbors’ wisterias are fading and going to seed). This exact same method can be used on recalcitrant lilacs purchased years earlier (lots of time for Mother’s Day) which never bloom again.
My son’s teacher was desperate for her obnoxious wisteria to bloom in time for her wedding, exactly 12 months away, as the reception was going to be at her home. I gave her the exact same advice I gave you. The following year, at the end of the year field trip, I was in the lot to pick up my son. His teacher (from the previous year) ran across the parking lot to thank me. It worked! She walked me over to her car to see her wedding album which she had been showing everyone, and lo and behold, that wisteria was in full bloom!
Sometimes, we just gotta show these plants who is the boss around here! ;)
Good luck!