Too much nitrogen is most likely the cause of your wisteria’s failure to blossom. Too much nitrogen will cause wisteria plants to generate a lot of foliage but very few, if any, flowers.
The habitat in which wisteria is growing is another cause of blooming issues. When wisteria vines are stressed, they may not flower but instead sprout leaves in the absence of full sun or sufficient drainage.
What can I give my wisteria to encourage blooming?
Feed wisteria plants each spring for the best results. A rose or flowering shrub feed will typically yield better results, while Miracle-Gro Growmore Garden Plant Food and Miracle-Gro Fish, Blood & Bone All Purpose Plant Food are both options. Feed plants in very well-drained soil with sulphate of potash in the summer as well.
How long does it take wisteria to bloom?
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.
See our commonly asked questions page for a summary of wisteria issues.
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.
Do coffee grounds work well with wisteria?
The garden can employ coffee grounds in a variety of ways. Although the impact is typically quite minimal, they can make the soil more acidic. Coffee grounds can enhance soil texture and drainage much like any other organic material. If you’re going to incorporate them into the soil, it’s better to compost them first. The compost pile benefits greatly from the addition of coffee grinds.
Wisteria doesn’t prefer acid, thus it typically doesn’t require a boost in acidity from coffee grinds. The optimal soil for wisteria is neutral to slightly acidic, therefore if your soil is alkaline to begin with, you only need to make it more acidic for wisteria.
Coffee grinds aren’t the best approach to lower the pH if your soil is alkaline, but they occasionally work. Although coffee beans are acidic, when you brew them, most of the acid is removed, leaving less acid in the grounds. Additionally, as the coffee grounds degrade, their pH does not remain acidic.
Purchase some garden sulfur or ferrous sulfate if your soil is too alkaline for wisteria. Applying coffee grounds might occasionally be helpful, but it probably won’t make much of a difference.
TL;DR: Spreading coffee grounds around your Wisteria is typically not beneficial.
Why is my wisteria acting up?
There are numerous reasons why this symptom could exist. Root conditions like honey fungus and Phytophthora root rot can affect wisteria. Vine weevil grubs, in particular, can harm the roots of container plants.
Can you fully prune the wisteria?
If the wisteria plant has a lot of dry, old branches and appears to be highly out of shape, it can be severely pruned back.
In order to renovate the plant, it is occasionally necessary to remove every branch, all the way to the main stem or even to the ground. Your wisterias will be inspired to grow new, robust branches as a result of this severe trimming.
McKenzie cautions that while the growth will be of much superior quality, the wisteria may not blossom for two or three years following a hard cut back.
A new pergola or arch can be created by “hard pruning” in addition to retraining the plant.
What kind of feed is ideal for wisteria?
For growing this most magnificent of horticultural spectacles, Alan Titchmarsh offers tips.
There are several benefits to spring arriving slowly. After a bitterly cold, rainy, and snowy winter, when army-blanket skies were the norm week after week and month after month, it is disheartening to have to wait so long for flowery joys.
Late springs, on the other hand, lessen the possibility of early development, which can frequently be severely scorched by late frosts. Due to unanticipated freezing temperatures at the end of the month, a friend’s wisteria, which had put on a spectacular annual display for fifty years, was dripping with depressing, grey flower trails in April last year.
Given that the buds didn’t even begin to open until the middle of April, they had high expectations for the kind of show that has become synonymous with their home this year.
How much I adore wisteria! When we got married, it graced the front wall of our humble three-up, three-down terrace house. I trained it with pride so that, during the six years we lived there, its territory grew year after year.
It was the common Chinese wisteria (W. sinensis), which for a long time was the only kind to grow in our gardens. Numerous cultivars with weird names and, in certain cases, strange colors and flower forms are available today, the majority of which are of Japanese origin.
At the Kawachi Fujien Wisteria Garden in Kitakyushu, Fukuoka, Japan, a wisteria tunnel is in full bloom.
If you’re planting a new one, make sure you like the color and blossom shape before purchasing a grafted plant because it will bloom more consistently and much earlier. A few inches above soil level, the graft union will be readily evident. There are strategies to induce blooming in older reticent plants, including those that weren’t grafted and were reproduced by layering or cuttings.
You need a sunny wall for wisteria. Giving it a wall with a north or east facing side is a waste of time. The most favored directions, where the wood will ripen most efficiently, are south and west. The pruning process itself is done twice a year. All questing growths that are required to increase the plant’s coverage should be tied in by July; all others should be cut back to around 1 foot. All sideshoots should be pruned to finger length in January. If you repeat this each year, your plant shouldn’t let you down.
Gorgeous Lodge House in Smeeth, Kent, close to Ashford, has a Georgian front covered in thick wisteria.
Wisteria is a twiner and doesn’t have sticky pads like Virginia creeper or aerial roots like ivy, so your wall will need some sort of support system. The least noticeable support is provided by strong horizontal wires attached to strong vine eyes screwed into the wall at intervals of 18in.
The likelihood of this happening can be reduced by regularly untangling the stems during winter trimming. A well-attached trellis can be used, but the snaking branches can get behind it and, as they fatten over the years, they can rip it from the wall.
Every March, you may encourage regular bloom and strong development by giving your wisteria a liberal serving of rose fertilizer, which is rich in potassium and magnesium, which assist flowers open up. If your wisteria has been pruned, nourished, and grown on a sunny wall for three or four years and still won’t bloom, consider it a failure, yank it out, and plant a grafted type that will catch up to it.
The wisteria-covered entrance to Dunsborough Park in Ripley, Surrey, is like the doorway to paradise.
The ancient standby Macrobotrys, which has flower trails that may reach a maximum length of two feet, is my personal favorite of the several types that are offered. The elegant white variety are just as striking as the lavender purple ones in the correct circumstances.
The plain W. sinensis, whose flower trails emit the most scrumptious aroma in spring sunshine, is a plant I would never avoid, especially if it were planted near a bedroom window that could be opened to let in the intoxicating scent.
Being so demanding with food and water, wisteria plants are difficult to grow successfully in pots and other containers. You can grow wisteria as a free-standing “standard” on a 5 foot bare stem if you don’t have access to a suitable home wall. It will require some support, but when I was a student at Kew Gardens, I recall enormous free-standing specimens there that were already well over a century old. They scuttled around a rusting iron structure that they had all but destroyed like boa constrictors.
To enjoy the pleasures of late spring and early summer in the company of one of the most stunning members of the plant world, all we need right now is the kind of sunny weather that was lacking earlier in the year.