Wisteria plants are romantic favourites for landscaping. With their woody, twisting stems, lush green leaves and strongly scented pendulous flowers, they are the showpieces of the spring garden. Wisterias need to be well supported as they are rapid growers and become quite heavy. But a well-tended and well-pruned wisteria vine is an heirloom, capable of gracing the landscape for generations. A wisteria plant that appears to be dead may not be, because several conditions cause the plant to stop producing leaves and flowers.
Seedlings or Cuttings
Wisteria grown from seed will produce beautiful green leaves and grow quickly but not flower for many years. You can wait 10 years or more for a wisteria plant started from seed to burst into blossom. During that time, the plant is healthy but the gardener or landscaper gets increasingly impatient. If you do not have the patience of Job and are eager for those fragrant pendants of lush flowers to appear in the spring, buy, inherit or beg a propagated plant. A grafted wisteria or a rooted cutting will establish itself and bloom within a year or two, sometimes as early as the next season. Don't uproot a wisteria that refuses to flower, thinking there is something wrong with the plant. Keep it properly trimmed and wait for the eventual payoff.
New buds form on stems that sprout from the main trunk or vine. Wisteria sprouts rampantly so pruning is the key to a healthy, flowering plant. Prune aggressive new shoots in summer and prune the entire plant for shape each winter, leaving two or three dormant buds on the shoots you keep as those will form spring flowers. If you keep the wisteria trimmed to shape and cut away dead branches or an excess of new growth so light reaches the entire plant, you should see green leaves and heavy, healthy racemes opening the next May. Pruning is the only real maintenance wisterias require so don't skimp on it. Trim back dead branches and damaged old wood to green, living wood and the wisteria should produce its greenery and flower clusters on schedule.
Sun and More Sun
Wisterias love sun and a shaded plant may not flower and may even grow skimpy with scant leaves. When planning a wisteria, survey the property to determine the sunniest spots for a well-supported plant. You may need to trim other shrubs or overhanging trees so the wisteria can get enough sun. Pay attention to how much sun your house blocks at different periods during the day. And watch out for hard freezes in winter. It is possible to kill a wisteria if the ground freezes hard enough. Mulching in the fall may help to hold in heat. Take care that the plant's roots are not growing in ground that holds a lot of water. Sun all day won't compensate for wet or frozen roots. If the plant looks dead after a cold winter, prune it and wait. It may produce buds and come back for the next season.
Wisterias don't need or like a lot of fertiliser. It's a good idea to enrich the soil annually with a light mix of compost or peat moss. But let that be the extent of it. Wisterias love neutral or slightly acid soil that drains well. Overfertilizing will first cause the plant to stop producing flowers and could ultimately kill it. Follow these soil enhancement guidelines when transplanting wisteria as well. Wisterias don't react well to transplanting and, if you have an older, larger plant, you may lose it if you transplant it.