When To Fertilise Wisteria

The optimum time to fertilize wisteria is in the spring. If you want to encourage blooming, you should fertilize the wisteria in the early spring, just before bloom. If you’re using nitrogen-containing fertilizer, hold off until after blooming.

Since wisteria doesn’t require much fertilizer, you only need to apply it once a year. If you miss your time to apply fertilizer in the spring, you can do so in the summer or fall as long as the fertilizer doesn’t contain nitrogen. In most zones, nitrogen fertilizer shouldn’t be applied after June.

When ought I should fertilize my wisteria?

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?

When the wisteria is young, the gardener concentrates on getting the plant to fill up the arbor, wall, or other space built for it rather than on getting it to bloom. Nitrogen promotes vigorous vegetative growth, therefore fertilize the young wisteria with a balanced fertilizer like 10-10-10. The plant needs a lot of potassium and phosphate when it is fully grown. You can only determine which of these nutrients the soil is deficient in through a soil test. Apply superphosphate, also known as 0-20-0, at a rate of 2 ounces per square yard of soil if the wisteria needs a phosphorus dose. A potassium deficit can be treated with 1 ounce of potassium sulfate per square yard.

What does wisteria require to bloom?

The simplest course of action is to check sure there is no problem because too much nitrogen is the most typical cause of wisteria blooming issues. There are two solutions to this wisteria not flowering issue. The first step is to enrich the soil with phosphorus. Applying phosphate fertilizer achieves this. Wisteria blossoms are stimulated by phosphorus, which also helps to balance nitrogen.

Wisteria plants can also be root-pruned to lessen the quantity of nitrogen they receive. To accomplish this, place a shovel in the earth in a circle around the wisteria. Root pruning should be performed at least 3 feet (91 cm) away from the trunk because doing it too close to the plant would cause it to die. Reducing the number of roots and, thus, the quantity of nitrogen those roots absorb is one approach to encourage wisteria to bloom.

If these solutions don’t help your wisteria blooming issues, you can determine if one of the other causes is the issue. Does the plant receive enough sunlight? Does it have adequate drainage? Are you fertilizing in the fall, when it should be done? Do you prune correctly? Are your wisteria’s blooming buds old enough?

Knowing how to encourage wisteria to bloom is crucial if you want to start enjoying the wonderful blossoms a wisteria produces. It might be difficult to wonder why wisteria isn’t blooming and not have the solution.

Why are my wisteria’s leaves turning yellow?

Insufficient soil drainage and excessive watering cause wisteria leaves to yellow. When the plant receives less water than necessary, the leaves of wisteria also turn yellow. The nitrogen imbalance in the soil also causes the yellowing of wisteria leaves.

Even though the main symptom is the same in all of these situations, by observing the plant, you can determine the cause. Watch to see how!

Overwatering Wisteria

If wisteria received more water than it required, the leaves would turn yellow. Wisteria leaves that have received too much water are limp and yellow.

Such overwatered Wisteria eventually develops brown leaves. Before watering the plant, you should use your fingertips to feel the soil.

Underwatering Wisteria

Yellowing of Wisteria leaves is another effect of underwatering. Due to the absence of water, leaves turn yellow but are dry to the touch.

Your Wisteria becomes stressed out by submersion. You’ll see that the plant’s leaves are disintegrating. If you see these symptoms, you need to act right away.

Make sure the soil has sufficient drainage while giving your plant regular waterings. To improve water retention, mulch the area surrounding your wisteria with bark and tree business chips.

Wisteria Vein Mosaic Virus

This virus causes the wisteria plant’s leaves to wrinkly. The veins and surrounding portions of the leaf veins of the infected plant turn yellow.

The leaves’ bleaching or yellowing cannot be reversed. Once the virus has infected a plant, it is challenging to eradicate.

The virus doesn’t do much damage to your wisteria other than discolor the leaves. Your Wisteria’s vigor is unaffected by the Wisteria Vein Mosaic virus.

Wisteria leaves curling and yellowing

Wisteria leaves become twisted and turn yellow due to an aphid infestation.

Aphids are tinier insects with wings that can harm a plant by sucking out its sap through the leaves. The wisteria’s leaves turn yellow as a result of their eating behavior.

If only a few aphids are present, your wisteria is unaffected. The health of the plant will decline if there is a significant aphid infestation.

You can get rid of small populations of aphids by using a water hose. Spraying Neem oil on the troubled regions will also get rid of them.

I typically oppose applying insecticides on plants. However, if the infestation is severe, feel free to.

Advice: If you see honeydew on the plant, you can tell if an aphid infestation is present early on.

Scale on Wisteria

On the stem and branches of the wisteria, scale pests can be seen as pimples. Scale cling on the susceptible plant and ingest its sap.

The wisteria’s leaves turn yellow as a result of their feeding activities. If you discover the infestation early, prune the plant’s diseased areas.

Rub minor infestations with a cotton swab that has been dipped in rubbing alcohol.

Neem oil can be sprayed over the plant to treat a severe scale infestation. Spray horticultural oil on the affected plant in the late spring.

Potted Wisteria leaves turning yellow

The main cause of yellowing leaves on potted Wisteria is probably overwatering. Make sure the wisteria plant’s container has excellent drainage.

If the soil is overly wet, check it out. The plant is root-bound if, in your opinion, this is not the case. Put the plant in a larger container.

Does wisteria benefit from tomato feed?

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.

Does wisteria benefit from bonemeal?

Use a 0-20-0 fertilizer to fertilize the wisteria in the late spring. This is sometimes referred to as bone meal or superphosphate. 3 to 5 pounds of fertilizer per 100 square feet should be applied. Wisteria shouldn’t be fertilized with nitrogen-containing fertilizer since too much nitrogen will make the plant’s leaves flourish at the price of its ability to blossom.

Tip

Think about the plant’s age. While some varieties of wisteria wait until the age of 15, wisteria do not blossom until they are at least six years old. Instead of starting with plants that were developed from seed, choose ones that were grafted or grown from cuttings because they typically bear flowers sooner.