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 do to make my wisteria bush bloom?
Mother Nature is a powerful force that acts independently and at her own pace. According to Iowa State University Extension and Outreach, this makes forcing wisteria flower buds, including those of Chinese wisteria (Wisteria sinensis) and American wisteria (Wisteria frutescens), to blossom virtually impossible. Sadly, despite the efforts of ardent gardeners, some vines never bear blooms.
There are a few things you can do to aggressively encourage blossoming even while the vine cannot be made to produce its dazzling, fragrant blooms. By using these techniques, you’ll improve the likelihood that your wisteria will produce an abundance of extravagant, vibrant blossoms and be well worth the effort.
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.
Wisteria blooms every year, right?
Your wisteria plant will often only produce one bloom from early spring to late summer. A second bloom has, however, occasionally been successful for some persons in the late summer or early fall. Of course, you won’t get as many blooms as in the first bloom, but you might be able to lengthen the bloom season and enjoy the spectacle for a little while longer.
Deadhead spent blooms as soon as they begin to wilt or droop if you wish to get a second bloom. Even while there is no assurance that you will receive additional bouquets, it might be worth you to try. Visit this post for all the information you need to know about when and how to deadhead your wisteria.
Your best strategy is to try to keep your plant as healthy as possible and in ideal conditions as the environment and growing conditions both play a significant part in whether or not your wisteria is likely to produce more blooms.
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.
Is a lot of water required by wisteria?
Location is the most crucial aspect to think about when producing wisteria. Since wisteria is a twining vine, it needs a strong support and regular pruning to stay in check. Wisteria thrives in open locations with easily manicured lawns surrounding them.
Although it will withstand a variety of soil types, this vine needs deep, rich soil that is slightly damp.
About the only significant requirement for wisteria vine maintenance after planting is pruning. Wisteria doesn’t need fertilizer because it grows quickly and is drought-tolerant, so it just needs a little water.
Does ancient wood allow wisteria to bloom?
In the preceding growing season, Wisteria generates its flower buds (“blooms on old wood”). Those buds were taken out if the plants were clipped from late fall to early spring.
Should wisteria be deadheaded?
Wisteria pruning is relatively simple, but it’s necessary if you don’t want it to spread beyond its designated area each year.
This can happen whenever the plant is dormant, from the moment the leaves have dropped to the conclusion of the winter.
- It’s crucial to just eliminate new growth to promote flowering because flowers grow on the growth from the previous year.
- Trim lateral branches in the winter, leaving only one or two buds.
This is to leave the main branch alone and to prune all of the stems that grow from it.
- Because the fruits of wilted flowers are poisonous, remove them frequently (deadheading).
Is wisteria compatible with Miracle Grow?
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.
What kind of fertilizer works best for wisteria?
Wisteria normally grows without much difficulty. This robust vine can grow quickly and doesn’t require particularly fertile soil to do so. However, there are several circumstances where fertilizer will aid in the growth of wisteria.
fertilizer is required for wisteria if
- Since the plant is young, you want to promote rapid growth.
- Even though it has had time to grow roots and receives enough of sunlight, it isn’t blossoming.
- It is being grown in a container.
- You got your soil analyzed and found a nutritional shortage as to why it isn’t flourishing.
Using the appropriate fertilizer is crucial in each circumstance. Wisteria is a nitrogen-fixing plant, just like other members of the pea family. You typically don’t need to add nitrogen to the soil of your wisteria because it obtains nitrogen from the air rather than the soil. If your plants receive too much nitrogen, they may start to produce more leaves and stems than blossoms.
If plants consume an excessive amount of nutrients or if substances that are only safe for plants in tiny quantities build up in the soil, too much fertilizer can also be harmful to the plants. It would probably be wise to save time and money by forgoing fertilizer if your soil is already productive.
We’ll go over each of the situations we described below and offer our recommendations for how to fertilize your particular Wisteria.
Helping Young Wisteria Grow Faster
Wisteria is typically trained over the first few years after planting to grow over a trellis, fence, wall, or other structure, or even into a tree shape. During this time, you should establish the wisteria and, if it was planted to cover a building, encourage rapid growth. Fertilizer can be useful in this case.
Wisteria typically doesn’t require nitrogen fertilizer, but since nitrogen promotes plant development and foliage, adding a little extra can hasten growth. During the first two or three years after you plant it, an all-purpose fertilizer with an NPK ratio of 10, 10, 10 is a suitable choice. (Assuming you purchased the plant from a nursery. It will take much longer for wisteria grown from seeds to attain maturity.)
Use of nitrogen fertilizer should end once the wisteria has grown to around the desired size and/or has begun to bloom. Fertilizer is frequently of no use to mature Wisteria, and too much nitrogen can prevent it from blooming.
Read on for our recommendations on how and when to apply fertilizer, or move on to our special advise on fertilizers for young Wisteria.
Getting Wisteria to Bloom
Inability to get Wisteria to blossom is one of the most frequent issues gardeners encounter, and fertilizer can occasionally help. Many popular garden plants, like Wisteria, are encouraged to blossom by the use of phosphorus and potassium fertilizers.
The following fertilizers work best to promote flowering in wisteria:
- fertilizer for flowers
- Fertilizers with phosphorus and potassium, like potassium sulfate and superphosphate
If you are having difficulties getting your wisteria to blossom, make sure you are not using nitrogen fertilizer as nitrogen encourages foliage growth at the expense of flowers. Additionally, it’s a good idea to keep Wisteria away from other plants that require nitrogen fertilizer. Sometimes Wisteria doesn’t flower because of fertilizer run-off from lawns.
But it’s crucial to keep in mind that if anything else isn’t right, fertilizer won’t be able to make Wisteria blossom. Wisteria requires a lot of sunshine to bloom, and occasionally buds are lost due to cold temperatures or improper trimming. Fertilizer won’t help under those circumstances. Sometimes wisteria just needs some time to grow its roots before it may begin to bloom.
Want to learn more about typical problems that lead to barren wisteria? The top 7 explanations for why your wisteria might not be blooming are covered in a different article on our website. Or scroll down to see our suggestions for wisteria fertilizers.
Growing Wisteria in Containers
In containers grown wisteria plants, regular feeding is required. You should add minerals to potting soil at least once a year because it depletes far more quickly than soil in your yard or garden.
Growing Wisteria in Poor Soil
Wisteria does require some nutrients from the soil, though not many. If you have a nutrient shortage or are aware that your soil is low quality, you should fertilize your plants accordingly. The nutrients your soil is lacking and how much you need to add can be determined via soil tests.
Of fact, even if a test indicates that your soil is deficient in nutrients, if your Wisteria is flourishing, it usually doesn’t need fertilizer. One of the plants that can occasionally thrive in poor soil is wisteria.