Wisteria

March 18, 2017

My husband has pruned my white wisteria so that there will be very few blooms! Please help me to help him to know why, when and how to prune it correctly so I will have my beautiful white wisteria bush back.  

Wisteria is a spring blooming vine that has its flower buds set when it goes dormant in the fall.  Pruning AFTER bloom is when it should be pruned. Pruning before it leafs out cuts off all the flower buds that are set.  Wisteria is a prolific vine which needs to be pruned hard annually.  Many gardeners prune it a little and then when it grows too much, they keep pruning throughout the summer season, which can also impact blooming. Prune as soon after blooming as possible, but no later than June 15. 

January 21, 2017

I have an amethyst wisteria plant that is about 5 years old.  Starting in June each year the leaves turn yellow with brown spots and start to fall off.  I am trying to cover my arbor.  My dreams of having a lush, shady place for my hammock are turning into a nightmare.  I've tried everything.

Wisteria is one of those tough plants that we usually try to slow down in its growth habits versus losing it to diseases.  The only disease I have seen with any regularity is powdery mildew, which this does not sound like.  What is the drainage like around the arbor?  Wisteria don't like wet feet.  That being said, if you have the same problem this year, as soon as you see it, take a sample of the foliage to your local county extension office. They can get it to our disease diagnostic lab and get a proper diagnosis, so we know what to control it with. If it is a common fungus and you get the same issue each year, a preventative spray may be called for, but first let's find out what it is.

December 2014

When is the best time to cut back a wisteria?  We planted ours 9 years ago when we first moved to Arkansas and it is almost bigger and heavier than the trellis that supports it and we want to re-route it. 

 Don’t touch it now, since flower buds are set for blooms next spring.  The time to prune wisteria is right after flowering in the spring—or if yours is not old enough to bloom, after it begins to start leafing out.  Heavy pruning is recommended annually to keep it in bounds and prevent it from spreading too aggressively. 

April 2012

I live in Mountain Home AR, I have a wisteria that just doesn't bloom. Is there a certain fertilizer I should be putting on it.. It's about 5 years old. Everybody else that has one is blooming. My next door neighbor has 3 large cedars fairly close to it, could that be a problem? If so is it too old to move? The base of it is about the size of a baseball bat. If I can't move it is there a way to take cuttings off it and get a root to plant it somewhere else. It is just doing beautiful where I have it in a corner on my fence and growing up the side and across the back. It's doing everything I want it to but no FLOWERS! Any advice would be appreciated. 

This is actually a fairly common question, but you wouldn't expect it with the amount of wisteria that is freely blooming all across our state right now. Wisteria can take its own sweet time getting established and growing before it slows down and starts blooming. It does best in full sun, but does need at least 6 hours of sunlight a day to bloom. It is not unusual for wisteria to take 6-8 years before it starts blooming, but once it does, it should every year. Prune it hard now that it is beginning to grow, keep it on its trellis or fence—do not allow it to grow up a tree. You can try root pruning the plant in June—take a straight edged shovel and make some staggered cuts in the ground as if you were going to dig it up and move it. You don’t do it solid line of cuts, but three or four in the root circle. This can slow down the top growth to regenerate roots, and sometimes it pushes it into setting flower buds for the next season.

October 2011

Could you please give me some information about the growing habits of Blue Moon wisteria? I have a young one that is currently planted against my wood privacy fence. I understand that it’s not as aggressive as its Asian cousins, but I’m still hesitant about leaving it there and am considering moving it or giving it away this fall. Is it safe to leave on the fence? Can I safely train it up one of my mature oak trees?

 Blue Moon is a new variety of Wisteria macrostachya which is a deciduous vine that is native to the south central U. S. It is similar to the American wisteria Wisteria frutescens. Both of these wisteria are considered better choices for the garden because they are not as aggressive as their oriental counterparts, but they still need a trellis to grow on. Blue Moon is supposed to bloom several times a season. I would not allow them on a tree for two reasons. Over time, the vines will become woody, which could girdle the tree, but secondly, for best blooming, they need full sun. Letting them grow on an old oak is going to be too much shade. Leave it on the fence, or add a taller arbor or something to grow on. The flowers are beautiful and fragrant.

July 2010

I have a wisteria that is over a large arbor. It bloomed this year for the first time. I read that you should prune (hard) the wisteria after blooming. Is this right? and what does hard pruning actually mean?

You are getting a bit late to prune. We like to prune wisteria back hard--cutting off roughly half of the growth after bloom to keep it in check. If it is allowed to grow, any place it comes in contact with the soil it will root. It can also grow up trees and the woody vines can girdle and harm the trees. If you have a large arbor you can simply keep it pruned to the arbor once it covers it. Try to get the pruning done as soon as the flowers finish--usually in early spring. Wisteria sets flower buds in late summer to early fall, so you don't want to keep pruning it all summer or you may interfere with flower bud formation.

August 2007

Are there two kinds of wisteria --one that blooms and one that doesn't? We have had a wisteria vine on an arbor out in the full sun for 3 or 4 years and it has never bloomed no matter how well we keep it fertilized, watered and pruned.

 Wisteria is one of those plants that call for patience. It grows at an alarming rate, but often can take up to 8- 10 years before it slows down enough to bloom. This is especially true if the plant was grown from seed. Avoid giving it too much fertilizer, as this simply aids in the growth rate. Keep it trimmed to the trellis that you have it on. When you do prune (if you do), prune it in the spring after it should have bloomed--not late in the season when it is setting flower buds. Once it begins to bloom, you will get more and more flowers every spring, so just wait.

August 2006

I have a plant that I hope you can identify. I purchased it a few years ago and would like to get another one. We can't recall where we got it or what it was. We thought it was some type of wisteria but are not sure. It smells wonderful and blooms from now until fall. It has beautiful dark purple clusters of blooms on shiny compound leaves. Any idea what I have?

 I think the plant you are looking for is commonly sold as an ever-blooming or tropical wisteria, but it is not in the same genus as our common wisteria. It is Milletia reticulata. It is hardy through central Arkansas. If you deadhead the spent blooms, it can continue to bloom throughout the summer. As to where to find it, I am not sure. I see it sporadically in nurseries or garden centers.

May 2006

Help. Is there any way to eradicate or control the spread of wisteria?

To prevent wisteria from becoming a weedy pest, make sure it has some type of trellis or support to grow on, and keep it pruned to stay on that trellis. If it is allowed to grow unchecked, it can root wherever it touches the ground, and take over. It should not be allowed to grow up into the trees, as it does form a woody stalk which can girdle the tree trunk or limbs it is growing on. It is tough to kill with herbicides, but Roundup and Remedy RTU can give you some control with spot applications. Be sure to only spray what you want to kill, and it should not be attached to the mother plant when spraying as the damage can spread.

June 2005

I have two beautiful wisteria plants that cover an arbor. They are approximately five years old, and have never bloomed until this year, and there were only about 5 or 6 blooms. They are in a shaded area, does this make a difference? What else could be the problem?

You are lucky if you got any blooms if the plants are shaded. Wisteria does bloom best in full sun, but needs a minimum of six hours. Don't overdo it with fertilizer around wisteria, as too much nitrogen will give you all growth and no blooms. Often, once established, they do fine with no supplemental fertilizer, but the more sun they get, the more blooms you will see.

December 2005

We planted a wisteria 3 years ago in a partially wooded area where it gets morning sun, afternoon shade. It has attached to two nearby tall trees, on either side, or grown 30 feet. It was fertilized the first 2 years, but not this past year, as I thought that might prevent blooms as strength all went into climbing. There is no way the 30 feet can be trimmed. At this point, I don't remember what variety, but it was a costly plant...It has a watering system.

You need to get the wisteria out of the trees. Wisteria will continue to climb for sunlight. It forms a very woody vine, which can wrap around trunks or branches, which can girdle and kill trees if it is allowed to grow unchecked. Try to plant it on an arbor or some other form of support--instead of living trees. It needs a minimum of 6-8 hours of sunlight. It can take several years before they begin to bloom. Avoid nitrogen fertilizer, since it only increases foliage growth, which they do rapidly enough on their own.