Wisterias thrive in full light, fertile soil, and both. Of the 10 species, three are grown the most frequently: Wisteria brachybotrys, Wisteria sinensis, and Wisteria floribunda, which are native to China, Japan, and the eastern United States (silky wisteria). All three species have significant growth rates and can extend out to a maximum of 20 meters (66 feet) against a wall or around 10 meters (33 feet) in trees. Wisteria can also be trained to grow as a free-standing standard in a big container or border.
Wisterias for pergolas and arches
The Japanese wisteria (Wisteria floribunda) is best exhibited hanging down from a garden structure like a pergola or arch since it has the longest flower sprays (or racemes) of all the species. They entwine in a clockwise motion while simultaneously bearing blooms and leaves. Lilac blue blooms and racemes as long as 1.2 meters (4 feet) are produced by Wisteria floribunda f. multijuga AGM in the early summer.
Wisterias for walls
Wisteria sinensis, often known as Chinese wisteria, blooms in the springtime before the leaves do. For example, Wisteria sinensis ‘Amethyst’ AGM has violet blue blooms with a reddish flush produced in dense racemes to 30cm (1ft) long in late spring or early summer. They twine anticlockwise and the racemes are shorter so they are best presented against a wall.
Silky wisteria (Wisteria brachybotrys), which can be grown against walls or on pergolas, with downy leaves and small racemes of 10-15cm (4-6in). White flowers with center yellow markings, a strong perfume, and 10-15 cm tall sprays of wisteria brachybotrys f. albiflora ‘Shiro-kapitan’ AGM bloom in the spring and early summer.
If you want to cultivate a wisteria in a big container
It is best to choose Wisteria fructens ‘Amethyst Falls’ because of its compact habit and rich clusters of lilac-blue blooms.
Always choose a wisteria that has been developed from cuttings or by grafting when purchasing one because seed-raised wisterias flower less consistently and take longer to bloom. The graft union should be seen as a swelling close to the stem’s base. Unlike species, named cultivars are virtually always grafted. Purchase your wisteria in flower or go with a specific cultivar to avoid disappointment.
Wisterias are offered for sale as container-grown plants at garden centers and online, and you can use the RHS Find a Plant tool to locate particular cultivars.
Wisteria should ideally be planted between October and April. Wisterias grown in containers can be planted at any time of the year, but fall and winter are the easiest times to maintain. Give them healthy, well-drained soil to plant in.
Wisterias bloom best in full sun, so pick a wall or pergola that faces south or west. Although blossoming will be diminished, they will still grow in light shade.
Wisterias are robust climbers that can grow to a height and width of more than 10 meters (33 feet). You’ll need to give support in the form of wires, trellises, or outside buildings like pergolas or arches against a wall. Wisteria can also be grown up a support or taught up a tree to create a standard. A wisteria can be grown in a border or container by being trained into a standard, which reduces its vigor.
If you want to grow your wisteria in a container, you’ll need a sizable one that is at least 45 cm (18 in) in diameter and is filled with potting soil with a loam basis, like John Innes No. 3.
Feeding
Use Growmore or Fish, Blood and Bone on your wisteria in the spring at the suggested rate listed on the packet. Additionally, apply sulphate of potash at a rate of 20g per sq m (1/2 oz per sq yard) on sandy soils (which have low potassium levels). Fertilizers for flowering shrubs or roses are another option.
Feed wisteria in containers using Miracle-Gro, Phostrogen, or another comparable flowering plant food. A different option is to add controlled-release fertilizer to the compost.
Although wisteria has a reputation for being challenging to prune, this is untrue. Once you’ve made it a habit to prune your wisteria twice a year, you should be rewarded with a pleasing flower show.
When you prune regularly, you reduce the excessive, whippy growth from July and August to five to six leaves, or roughly 30 cm (1ft). This increases the possibility of blossom buds budding and permits the wood to ripen. Then, in February, trim these shoots even more to two or three buds, or around 10 cm (4 in), to tidy up the plant before the growing season starts and make it possible to observe the new flowers.
When your juvenile wisteria has completely covered a wall or other garden structure, start the routine pruning to promote flowering.
Small gardens benefit greatly from the training of wisteria as a free-standing standard in a border or container.
Wisteria can be trained to ascend into a tiny tree’s canopy, however doing so could eventually harm the tree. Pruning will be challenging if the plant develops into a huge tree, and a dense leaf canopy will affect flowering.
Increase your wisteria stocks by layering in the summer, taking softwood cuttings in the spring to mid-summer, or taking hardwood cuttings in the winter since seed-raised wisteria can take up to 20 years to flower.
Wisteria is typically propagated via grafting in professional nurseries, however layering is the simplest and most dependable technique for home gardeners.
Established wisteria can produce hanging, bean-like seedpods after a lengthy summer. While wisteria plants grown from seeds are typically of inferior quality, you might want to try growing wisteria yourself.
- After the leaves have fallen, gather the seedpods and let them ripen in an open tray.
- When the seed is ready, twist open the pod and sow it 2 cm (3/4 in) deep in seed compost.
- Before planting if the seed is dry, soak it for 24 hours.
Poor flowering
Poor flowering is the most frequent issue for backyard gardeners, and it can be brought on by a variety of factors, such as:
- Young plants can take up to 20 years to flower, so acquire a plant that is already in bloom or go with a certain cultivar because they are typically grafted to avoid disappointment.
- Examine your pruning methods and timing because early and midsummer trimming will prevent the growth of flowers the next year.
- Wisteria flowers best in broad light; deep shadow produces few, if any, flowers.
- Water your wisteria during periods of drought from July to September because a lack of water during this time will influence the development of flower buds the next year.
- Flower buds may drop before opening as a result of spring frosts, which can harm or deform growing flowers.
- Applying sulphate of potash in the spring will encourage bloom production for the next year in soils that may lack potassium.
- The damage caused by pigeons or mice can be identified by torn petals or distinctive teeth marks.
Other problems
A mature, seemingly robust wisteria will occasionally pass away and be replaced by a new, healthy branch emerging from the ground. Failure of the wisteria graft may be the reason of this.
Wisteria is sensitive to both of the fungi that cause phytophthora root rot and honey fungus, which are less frequent causes of failure.
Unusual brown blotches and marks on the leaves, typically with a yellow edge, may be a sign that a fungus has infected them. Viruses can also harm wisteria and powdery mildew.
Infestations of scale and, less frequently, wisteria scale can affect wisterias.
While we hope this information may be useful to you, we always advise reading the labels on your plants that provide care instructions.
Where shouldn’t wisteria be grown?
In order to support the massive vine, the wisteria’s root system extends out widely and dives deep. Do wisteria roots exhibit aggression? Yes, wisteria’s root system is highly aggressive. Avoid planting wisteria next to walls or walkways because of its extensive and strong root system. These are easily harmed by a wisteria’s root system.
Experts advise inserting a corrugated panel about 6 feet (1.8 m) long and several feet (1 m) broad beside the plant to redirect the roots if you find a wisteria close to a building or pathway.
Which month is ideal for wisteria planting?
The best seasons to plant wisteria are spring or fall, and you should put it in full sunlight to ensure that you get to view its lovely blossoms. A wet, well-draining soil is ideal for wisteria.
Types of wisteria:
There are two varieties of wisteria: Asian and American. Although aggressive growers, Asian wisterias are well-known for their stunning blossoms. American wisterias are less aggressive and still produce beautiful blossoms. Compare the most popular wisteria varieties.
Flower color:
Wisteria comes in a range of colors, such as white, pink, and blue tones, in addition to the well-known purple blossoms. If you believe you have seen a yellow wisteria flower, it was probably a golden chain tree (Laburnum).
Foliage:
Wisterias are deciduous, which means that when the weather becomes chilly in the fall, they lose their leaves. The misunderstanding is occasionally brought on by a different vine known as evergreen wisteria (Millettia reticulata).
Avoid planting aggressive wisterias close to your home as they can cause damage and have even been known to destroy buildings.
Wisterias can be grown in full sun or partial shade, but to promote healthy bloom development, make sure the vines get at least six hours of direct sunlight everyday. If you reside in a colder area, pick a planting location that is protected because a heavy spring frost can harm the flower buds.
Create a planting hole that is the same depth as the plant and twice as wide, then level the plant with the soil surface. Because the vines will soon fill in, you should space your plants at least 10 to 15 feet apart along the support structure.
Wisterias don’t need much care once they are planted to promote healthy growth. Water frequently over the first year until the roots take hold.
After planting, wisterias could take some time to come out of dormancy and might not start to leaf until early summer. They will leaf out at the regular time the following spring, but don’t be surprised if they don’t bloom. Wisterias take three to five years to reach full maturity and may not start blooming until then.
Wisterias grow quickly and can reach heights of up to 10 feet in in one growing season. That works out well if you need to quickly cover a fence or pergola but don’t want the vines to take over your landscape. Regular pruning (once in the summer and once in the winter) not only controls wisteria’s growth but also encourages more robust flowering by creating a framework of horizontal branches and causing spurs to grow at regular intervals.
Cut back the current year’s growth to five or six leaves in July or August, or roughly two months after the plant flowers, to get rid of stray shoots and make short branches that will produce flowers the following year. Summer pruning needs to be done more frequently. Re-prune the plant in January or February while it is dormant by removing two or three buds from the growth from the previous year.
The first few years of wisteria’s growth are crucial for creating the desired framework for the plant’s development. As soon as your wisteria begins to grow, start connecting particular lateral shoots to its support structure. You should also cut down any extra growth. An aggressive pruning may be required on elder plants to promote the growth of new branches. Cut down aging branches to the main primary stem to accomplish this. The spaces will soon be filled with new side branches that can be connected back into the support structure.
Visit the Royal Horticultural Society to view a video on how to prune wisteria vines properly.
Does wisteria prefer shade or the sun?
The greatest way to utilize wisteria’s breathtaking beauty and incredible vitality is to grow it as a little tree, or standard. Long racemes of sweet-smelling May flowers hang down from soft, pruned leaf heads and sway slightly with each breeze. The compact head of a Tree Wisteria looks amazing in a mixed bed of perennials, bulbs, and annuals. The impression is beautiful and dignified.
Please be aware that wisterias typically take a while to emerge from dormancy after planting. Please be aware that your plant won’t start to leaf out until early summer. It will thereafter leaf out at the usual time in succeeding years (midspring).
Choosing a Location: Wisterias grow and flower most effectively in areas with plenty of sunlight, preferably at least 6 hours every day. They do well in any kind of soil as long as it drains well.
In order to plant your bareroot Wisteria, take off the packing and give the roots a few hours in a bucket of water. Then, dig a hole that is both large enough to permit the roots’ spread and deep enough to allow you to set the crown, or the location where the stem and roots converge, 1 inch below the soil’s surface. Insert the roots into the planting hole and arrange them naturally or like the spokes of a wheel. The roots of many woody plants are brittle, so use additional care when positioning them in the planting hole to prevent breaking them. With one hand holding the crown 1 inch below the soil’s surface, use the other to push soil into the hole while circling the roots to prevent air pockets from forming. Then, using both hands, compact the soil close to the crown. To create a basin, create a rim of earth around the perimeter of the planting hole. This basin is used to collect, hold, and direct water to the roots. Finally, thoroughly immerse the plant.
Please be aware that once bareroot plants are taken out of their packing, they dry up rapidly, especially on a sunny, windy day. Until you are ready to plant, we strongly advise that you keep the roots wrapped in wrapping material.
Staking: To keep their heads aloft in severe gusts, tree wisterias need additional support. After planting, drive the wooden stake that came with your tree 6 to 12 inches deep and 1/2 inch away from the plant’s trunk into the earth. Using the plastic tie tape that came with the tree, affix the trunk to the stake numerous times, spacing them apart by about 8 inches. You’ll need to swap out the original stake for a bigger wooden stake or a sturdy steel pipe as the head and trunk grow bigger. Check the tree every spring and autumn to ensure that the stake is securely in place and that the tie tape used to attach the trunk to the stake is not excessively tight and preventing the trunk from expanding. Plants need to be firmly staked at all times.
Watering and Fertilizing: To hasten wisterias’ establishment in the first year after planting, they require the equivalent of 1 inch of water each week. If the sky doesn’t provide enough moisture, water deeply once a week. Plants that are established only require irrigation during extended dry spells. Wisterias don’t need much, if any, fertilizing because too much fertilizer prevents blossom. Give plants a gentle feeding of 5-10-10 or 5-10-5 at a rate of 3/4 cup per square yard in the early spring each year if your soil is particularly weak or sandy.
Overwintering: For the first few winters after planting, cover the main stem with a piece of plastic tubing in cold-winter conditions like ours here in Litchfield (Zone 5 [-20F]). To encircle the stem, make a straight incision from one end to the other and pry the cut open. (Precut tubing could be available at your nearby garden center.) To stop wind and frost from damaging branches on older specimens, cat’s-cradle bind the branches together using twine to form a web of intertwined strings.
Pruning: Tree Wisterias need to have the long, twining branches they generate in the summer pruned lightly but frequently in order to maintain the globe shape of the head. A couple of weeks prior to the first date of your first frost, they also require one severe pruning in late summer or early fall. Remove all branches that are in the wrong place and reduce the current season’s development to just 5 to 6 huge buds (leaving stubs that are about 6 inches long). This drastic haircut inhibits growth and promotes the transformation of some leaf buds into flower buds. Don’t let pruning errors keep you up at night. Wisterias are highly understanding plants; strong growth the following season will give you another chance.