Vines - Wisteria
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  (April) We have had a Wisteria in our yard now for about five years. It has never bloomed. Our neighbor has one too. We both bought them at the same time from the same place. Theirs has not bloomed either and is about 10 times the size of ours. My husband keeps our trimmed down so it doesn't climb into the top of the surrounding trees. My husband is threatening to cut it down but he is giving it a stay of execution until we hear from you.

  Wisteria can take its time in beginning to bloom, but once it begins, it should continue. Avoid heavy nitrogen fertilizer around the plant -- it is in the pea family and can grow quite fast on its own. Too much nitrogen will encourage rapid growth, which often leads to giant plants with few to no blooms. Wisteria does need a minimum of six hours of sunlight a day to bloom, and should not be pruned past mid summer--since they set flower buds in the fall for the following spring bloom. Any pruning is best done as soon as flowering finishes in the spring (or for non-blooming plants, after they have fully leafed out.) Unfortunately, it is too late to do anything about blooms for this season, but you can begin work on next year. One method that can work to begin initiation of flower buds for next year, would be to root prune the plant in July or early August. To root-prune a plant, use a straight edged shovel, and dig straight down in a staggered pattern in a rough circle about a foot away from the plant. This should cut some roots (not all, because it is not a complete ring) and slow down the top growth. Often this encourages the plant to begin setting flower buds. You can give the plant a little super-phosphate and let it get a little on the dry side-again trying to slow down growth. Good luck and hopefully, you will see flowers next spring.

  (June) 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.

  (June) One day last week, I removed several green seed pods from a wisteria vine alongside a walking path. I want to plant them in my yard near a fence. I worry that I should have waited for the seed pods to become dry and brown before harvesting. Is it possible for these green seed pods --granted, they were pulled early in the growing season -- to sprout and grow properly?

  If the pods were not mature it is unlikely you will get any sprouts. I would also caution about planting wisteria from seed. Seed grown wisteria can take up to 8 years before it begins blooming. since it roots so readily -- too readily in some opinions, I would find someone who has a plant and get cuttings or small plants. Or invest in one, and you will have as many plants as you want. Be sure to keep it trained to the fence, since wherever it touches the ground, it will root.

  (October) We have a wisteria which needs trimming. Will it be OK to trim it now, or should we wait?

  It is too late to prune any plants which bloom in the spring. If you prune it now, you won't be killing the plant, but you will be removing the flower buds it is setting now. Plants that bloom in the spring, set flower buds in the fall. Try to prune your wisteria drastically after bloom each year, so that you allow ample room for it to grow. It can be a vigorous grower and quickly take over if you aren't careful.

  (November) I have a wisteria vine that is just that, a vine with no blooms. It is about 3 years old, has a thick, sturdy vine, and has wrapped itself around a nearby tree. The tree is severely pruned because of electrical wiring so I thought it would be ideal for it to cling to. What do I need to do in order to insure blooms next spring.

  First of all, keep in mind that wisteria needs plenty of sunlight to bloom -- a minimum of six hours. Often when they attach to a tree, they move up the tree in search of sunlight. Allowing them free reign on a tree can lead to problems down the road. Wisteria forms some strong, woody vines. This can lead to possible girdling of the tree. It is usually best to train wisteria to a trellis or fence away from nearby vegetation. Avoid excessive nitrogen around wisteria, as it can simply lead to rampant growth and few blooms. By now, the flower buds are set for next spring, so nothing you do now will change things.

  (December) Please tell me how to kill a wisteria vine. I have tried several things including having it sprayed and nothing works. It's taking over my farm. Now that it is dormant or almost dormant, is there something to treat it with to prevent it coming back?

  Wisteria is not an easy plant to kill. At this point, pull out or chop up as much of the plant as you can and dispose of it. Remedy RTU which is a formulation of Triclopyr Ester can work on woody plants,-(including poison ivy, honeysuckle, and English Ivy) but the smaller the plant the better the treatment, plus you will have less dead foliage and mass to deal with later. Treat the cut edges of the plants with the herbicide, directing it where the plants are. Always read and follow the label directions, and avoid spraying on a windy day where herbicide drift could hurt nearby desirable plants. Regardless of how thorough you think you are, you will probably still have some wisteria sprouting next year. Spot spray as needed. You do not need to cut the plants back to treat; the spray is effective on leafy material as well. Although the label often says Remedy RTU can be used year-round, avoid spraying in the intensely hot, dry summer months or if snow is on the ground.

  Last year I pruned my wisteria back hard hoping to get blooms. It grew well, but I never saw a flower. What did I do wrong, and what can I do now or this year to insure flowers?

  Wisteria plants bloom in the spring, and set flower buds in the fall. Any pruning done last year, would have had impact on this seasons blooms, not last years. Hopefully, the plant is getting plenty of sunlight. Yearly pruning helps to keep this plant in bounds, and should help in flowering. Wait until after the bloom period has passed before doing any pruning. Young vines often don’t bloom for a few years, but provided they are in the sun, once they begin blooming, they should continue every year.

  I have a wisteria that is about 3 years old that has never bloomed. It is not in full sun, but has sun for most of the day from probably about 9:00 a.m. until 5:00 p.m. It is a healthy looking plant that has grown tremendously, but has never bloomed. Can you tell me why it doesn't bloom?

  Wisteria can take up to 8 years to begin blooming if it is grown from seed. Age could be a factor. Nitrogen fertilizer or rich soil can also produce foliage growth to the exclusion of flowers. Try avoiding nitrogen around it, and apply some super phosphate instead. Prune it back hard to keep it in bounds, and be patient. With time and the sunlight it is getting, it should begin to bloom.

  We have a large, apparently healthy wisteria in our yard, but it hasn’t bloomed in the six years we have lived here. It was full grown when we moved in. We must prune it annually because of its location in the yard. Are there varieties that don’t bloom? What suggestions do you have regarding pruning and/or feeding which might help?

  All wisterias have the capability of blooming, provided they get sunlight. They will not bloom in the shade. If the plant was grown from seed (which you have no way of knowing) it typically won’t bloom for eight to ten years. Wisteria plants are very fast growing vines, which if given extra nitrogen, may grow so fast that they don’t set flower buds. Avoid nitrogen around the plant, and make sure it gets plenty of sunlight. Try using some super phosphate fertilizer now and again in four to six weeks. Severe pruning should be done now (or when blooming, immediately following bloom). Wisteria plants will set their flower buds in the fall, so avoid pruning after mid July, or you may interfere with flower buds.

  I have 2 wisteria bushes which have never bloomed. One is at least 10 years old and is in full shade. I planted the second one in full sun after I learned they require lots of sun to bloom. It is about 4 years old and very bushy. Can you tell me what I should do to encourage blooming and when and how much pruning can I do?

  Unfortunately, wisteria can take its own sweet time in blooming. Try to avoid heavy nitrogen fertilizers. Stick more with a complete 10-20-10 type, applied once a year in the spring, and you can also apply an application of super phosphate to help with flower set. The plant in the shade will never bloom.

  Wisteria has plagued me for years. I followed your advice last year about pruning an old wisteria vine. Now I have one third the vine and still no flowers. Another friend wants to plant wisteria on a trellis and wants to know the difference between Japanese wisteria and American wisteria. IS one not invasive? How do I make them bloom?

  There are actually three different species of vining wisteria that have similar blooms: Japanese wisteria is Wisteria floribunda, Chinese wisteria is Wisteria sinensis and American wisteria is Wisteria frutescens. The most commonly grown plant is the Japanese wisteria. All three of the plants are prolific vine producers and can grow thirty feet or more. Japanese wisteria is more invasive than the others. If you wanted to extend the bloom period, you could plant all three, since the Japanese variety blooms first--typically April, while the Chinese blooms in May and the American variety blooms June to August on the current season growth. For that reason, you can keep it pruned to a more manageable size. The oriental varieties set their flower buds in the fall for spring bloom and should be pruned after flowering. The American variety should be pruned hard before growth begins. All will perform best in full sunlight, and need little in the way of nitrogen, since rapid growth can preclude flowers. For the old non-blooming plant, keep it pruned to a manageable size and fertilize with super phosphate. Hope you’ll have some blooms next year.

  I have a wisteria vine that is over six years old, and it has never bloomed. It has grown like a weed and has taken up too much space in my yard, but I’m afraid to prune it. When should I prune it so that I don’t interfere with flowers--if I ever get any? Is there anything else I can do to encourage flowering?

  Wisteria plants are fast growing plants, that often get into a growth phase which takes away from blooming. Limit fertilization near these plants, particularly nitrogen, which will lead to even faster growth. Make sure the vine is in plenty of sunlight, or they’ll never bloom. Prune the plant back hard after the normal bloom period has passed. Do this every season to keep the plants in check. Hopefully, you’ll begin to see some flowers.

  We moved into a new home a couple of month ago, and I have begun to take inventory of my yard. Many of the plants are dormant, so I will have to wait until spring to be sure of what I have. I do know there is a large, and apparently old wisteria plant in my yard. The trunk coming out of the ground is quite large and matted with vines, and the vine is growing up a couple of trees and seems to be running rampant. How far back can I cut it and when? I don’t want to lose the plant, but I sure don’t want wisteria everywhere.

  Enjoy the blooms on your wisteria this spring, then chop it off. I would really prune hard to get a handle on this plant. I prefer a self-contained plant. As large as your trunks are, they would probably support the top growth as a stand-alone plant. Cut the vines back to the very top of the main trunk. This should give you a blooming "tree" of wisteria next spring. You may find root sprouts after such a severe pruning, and look for wild seedlings that may have arisen from this plant. I agree with you that it is a pretty plant, but watch out, they are a plant that if you give them an inch, they will take a mile.

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