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. Wisteria vines that lack full sun or sufficient drainage may be strained, and while they will develop leaves, they will not flower.
What can I give my wisteria to encourage blooming?
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.
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 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.
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.
How can you encourage wisteria to grow?
A spectacular, opulent vine known as wisteria will enchant you with its heavenly blossoms year after year. However, the profusion of flowers that cover a pergola, wall, or arbor isn’t always simple to achieve. You’re not the only one who is interested in learning how to encourage your wisteria vine to produce more flowers.
You should concentrate on the surroundings and general health of the plant if you want to encourage your wisteria to blossom and generate more blooms. Make sure it receives the appropriate amount of water, sunlight, and nitrogen from the soil. Correct Wisteria pruning can also promote more blooms.
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.
How long does it take wisteria to bloom?
Wisteria can be grown against a house wall or another robust building, like a sturdy pergola. Wisteria can be grown in a container, but only if done so as a conventional tree and with regular trimming to keep its shape. This is a highly labor-intensive option.
How to plant wisteria
Wisteria can be planted in spring or fall. Plant at the same level as it was in the original pot and water in thoroughly after thoroughly preparing the soil to guarantee a proper root run. Like an espalier fruit tree, tie the stems to horizontal galvanized wires connected to the wall. Remove all but one stem if it is climbing a pergola, and tie this stem to the post.
How to plant wisteria in a pot
Wisterias can be planted in pots, but because they are hungry plants, you will need to feed them frequently. Choose this option only if you’re training your wisteria to be a standard. Use a quality tree and shrub compost and the biggest pot you can fit. Plant at the same height as it was in the first pot and give it plenty of water.
How to care for wisteria
The wisteria plant is ravenous. During the growing season, fertilize once a month with a high potash fertilizer to promote greater flower blooming. Weekly wisteria fertilizer and watering. Use organic mulch in the fall, such as well-rotted horse dung or homemade compost, to protect your plants.
How and when to prune wisteria
Wisteria should be pruned twice a year in August and February. Focus on integrating the plant into the support throughout the first few years. This entails cutting back side shoots to five buds in early August, training in strong side shoots, and removing very low branches.
How to prune wisteria in summer
Wisteria that is pruned in the summer will produce short spurs that will transport the spring blossoms.
- Cut the long, robust shoots back from the base of the current season’s growth to a few buds.
- Choose a few sturdy shoots from young plants (less than three years old) to tie to wires or a trellis.
- Simply cut back side shoots on older wisterias to the base of your strong shoots.
Expert David Hurrion demonstrates how to prune wisteria in the summer in this little video. He demonstrates which stems to cut and how much to remove precisely:
How to prune wisteria in winter
By pruning both in winter and in the summer, you can promote the growth of the short spurs that bear the spring blooms. Anytime between late October and March is the dormant season, so do this.
- Connect fresh growth to the main structure to increase its support
- Cut remaining long stems back hard.
David Hurrion demonstrates how to control robust, leafy growth so it doesn’t cover budding flower buds in this video on winter-pruning wisteria:
How to propagate wisteria
Few gardeners cultivate wisteria; most opt to purchase a plant instead because it can take up to 20 years for a wisteria to bloom from a cutting. However, take softwood cuttings in the middle of April if you’re up for a battle.
- Young stems should be cut into lengths and trimmed to 10 cm, just below a leaf joint.
- Leave roughly four leaves at the top of each cutting after removing the lower ones.
- Fill pots with cutting compost, then fill them with water and let the water drain.
- Cover the cuttings with a clear plastic bag after inserting them into the pots so the leaves don’t contact.
- Make sure the cuttings are kept moist by keeping them in a well-lit area.
- Remove the bag and pot after growth is visible.
Growing wisteria: problem solving
Lack of blossoms is the most frequent issue wisteria gardeners encounter. Expecting blooms before the plant is four years old may be impractical because wisterias take their time to bloom.
David Hurrion provides tips on where to plant your wisteria, how to prune it, and how to feed it to get the most blossoms here.
Will wisteria damage my foundations?
In the spring, a house covered in wisteria looks magnificent. Can the roots harm your foundations, though? In our Quick Tips video, Catherine Mansley from BBC Gardeners’ World Magazine explains: