How to Grow Wisteria

Nothing beats a wisteria in full bloom, sprawling across a pergola or covering a wall with dramatic lilac or pink flowers. These long-lived climbing plants are a commitment, but they're easier to grow and train than you may think. In return for your effort, you can enjoy an incredible display of flowers each spring.

A wisteria is one of the most stunning climbing plants you can grow, but it sometimes has a reputation for being tricky to control. Whether you want to train it up your house for English cottage vibes, over a pergola or create a wisteria umbrella in your garden, this guide will help you plant, care for and prune your wisteria.

Most people will only have space for one wisteria in their garden, so it's worth putting some thought into what species and cultivar will best suit your space. The colour of the flowers is likely to be a prime consideration. Lilac, mauve and lavender-blue are the most popular colours, but you can also buy wisteria with white, pink or deep purple flowers.

Wisteria sinensis (Chinese wisteria) and Wisteria floribunda (Japanese wisteria) are the most popular species grown in the UK. Chinese wisteria is very popular for training up walls. It flowers on bare wood in April or May and produces short, plump racemes of highly fragrant flowers. Japanese wisteria has the characteristic long racemes you see hanging down from arches and pergolas in English country gardens. The flowers bloom alongside new leaves in May or June.

Wisteria brachybotrys (silky wisteria) is also native to Japan, but it's less aggressive than other Asian wisterias, with delicate flowers and velvety seed pods. There are also two species of American wisteria: Wisteria macrostachya (Kentucky wisteria) is a very hardy, fast-growing wisteria, whereas Wisteria frutescens (American wisteria) is less aggressive, making it suitable for small gardens. These three species tend to produce shorter racemes of flowers compared to Chinese and Japanese wisteria.

 

Where to plant wisteria

Wisteria flowers best in full sun, so choose a south or south-west facing area that's sheltered from cold winds to plant your vine. It will grow best in fertile, well-drained soil. Wisteria don't like being moved, so take your time to find the right spot in your garden.

When you look at an older wisteria, you could be forgiven for thinking that your vine is a wisteria tree, as the central "trunk" is so thick and woody. It's important to plan ahead for this when deciding on a support structure. A lightweight trellis won't cut it; a wisteria needs to be trained against a wall, tied into galvanised wires, or over a sturdy pergola or arch (set in concrete). This structure supports the weight of the plant, which means a wisteria's root system is very unlikely to cause damage to the foundations of the building it's planted near.

If you don't have a suitable wall or structure to train a wisteria up, there is another option. You can train wisteria into a standard form, to look like a tree, and a wisteria umbrella – where the vine is trained vertically, then given a horizontal round support to spill over and down from – is an impressive sight. This method of training wisteria enables you to control the size of the vine and grow it in a smaller space in the ground or in a pot.

It's possible to grow wisteria in trees, but this isn't ideal for the wisteria or the tree. The weight of a mature wisteria will likely damage a small tree, and if the vine is left to scramble up a large tree, it's almost impossible to prune, which means you won't get the best display of flowers. 

 

When to plant wisteria

The ideal time to plant wisteria is between October and April. This gives the plant a chance to establish itself before the main growing season. You can plant wisteria at other times of the year, but it may need a bit more care and attention. Avoid planting when the ground is frozen.

 

How to plant wisteria

Before you plant your wisteria, you need to put your support structure in place. If training it up a wall, the best method is to use a tensioned wire system with horizontal strands of galvanised wire and vine eyes screwed into the wall at regular intervals. Space the wires about 45 cm apart.

You want to plant a wisteria around 30 cm from the base of a vertical support (such as a pergola) or 50 cm from a wall. Dig a hole around twice the width of the rootball and plant your wisteria plant at the same depth it was in its pot. For grafted plants, the graft union should be just above the surface. Angle the rootball slightly toward the wall and prop a bamboo cane between the plant and the wall if the wisteria isn't long enough to reach the first wire. 

Growing wisteria in pots

Wisterias are hungry plants that need plenty of food and water. They're not the easiest plants to grow in pots, but it's doable if you choose the right plant and give it sufficient attention. Either opt for a standard form, which is more restricted in size, or a less vigorous variety such as Wisteria 'Amethyst Falls'.

When it comes to choosing a container, bigger is better – I'd always opt to grow wisteria in planters over pots. Use a peat-free tree and shrub compost and plant your wisteria at the same depth it was in its growing pot. Refresh the compost for potted wisteria annually in spring.

 

How to train wisteria

Your aim in training a wisteria is to create a framework of stems along your support structure. The flowers will bloom on side shoots from this framework. When training a wisteria on a wall, use the same method you'd use to train an espalier fruit tree. Tie in your leading stem to each of the horizontal wires as it grows and select a couple of strong lateral stems to tie in horizontally along the wires. In winter, trim the leading shoot back to a pair of buds to encourage it to branch out along the next set of wires.

To train a wisteria up a pergola, you want to focus on guiding a handful of stems up to the top of the structure, tying them in as they grow, before allowing the wisteria to branch out across the top of the structure.

 

How to care for wisteria

Newly planted wisteria will need regular, deep watering to help them establish strong roots. This is particularly important if you have sandy soil that dries out quickly. Deep watering is important for wisteria in pots, too. Rather than spraying the surface of the compost every day, drench it once a week (more frequently during dry spells) until the water runs from the bottom of the pot.

Feeding a wisteria with rose fertiliser in March can help promote flowering. Plants grown in pots will need more regular feeding during the growing season – use tomato feed or another fertiliser high in potassium (comfrey feed works well as a DIY option). Avoid fertilisers that are high in nitrogen, as this will encourage the plant to produce leafy growth at the expense of flowers. 

Wisterias are hardy in the UK and don't require winter protection when grown in the ground. If you have a wisteria in a pot, you may want to wrap the pot in fleece to protect it from extreme cold temperatures.

 

How and when to prune wisteria

Pruning wisteria isn't difficult, but you do need to use the correct method to ensure a good display of flowers and prevent the vine from exploring further than you'd like (such as into your gutters or windows). You should prune wisteria twice a year: 

• Cutting back wisteria in July or August helps encourage the development of flower buds. Shorten the long, whippy shoots to five or six buds from the base.

• In January or February, when the plant is dormant, cut the trimmed stems back to two or three buds. At this time of year, it's also easy to spot and remove any dead or damaged stems and carry out structural pruning to maintain the desired shape.

Young plants don't need so much pruning. Focus on training your wisteria by tying in strong shoots to create a framework. Once it has reached your desired height and spread, you can then prune it as above. 

 

How to propagate wisteria

Growing wisteria from seed is a project for only the most committed, experimental gardeners, as plants propagated in this way can take up to 20 years to flower. Taking wisteria cuttings or propagating by layering is more reliable, though you may still have to wait five years or more for the young plants to flower. Most people just buy a wisteria plant.

How to take wisteria cuttings

You can propagate wisteria from softwood or hardwood cuttings. The new plant will be identical to the parent plant.

Take softwood cuttings in spring or early summer from a non-flowering shoot. Cut a section at least 10 cm long, cutting just above a leaf node. Trim your cutting so the base is just below a leaf node, remove any lower leaves and pinch out the tip. Dip the cutting in hormone rooting gel or powder, then insert it into a pot of cutting compost, water, and place in a propagator or cover with a plastic bag.

Find out how to take hardwood cuttings in late autumn or winter.

 

Common problems

The most common issue people run into with wisterias is poor flowering. If your wisteria isn't flowering, this could be for several reasons:

• Your wisteria isn't old enough. Most wisteria take 3–5 years to flower. If you have a baby plant, you may just need to be patient and give it a bit longer. Grafted plants typically flower sooner than plants grown from seed.

• The vine hasn't been properly pruned. If you're inherited an overgrown wisteria, cut all the stems back to the main framework in winter to renovate the shrub. This should give you a good display of flowers the following year.

• The soil has the wrong balance of nutrients. Too much nitrogen causes a wisteria to put on lots of leafy growth. Use a fertiliser with higher levels of potassium, such as those marketed for roses or tomatoes. Sandy soils typically have lower potassium levels, so you may need to give the soil a boost with sulphate of potash.

• The wisteria doesn't get enough sun. Wisterias really need a sunny spot to flower properly. If you plant one in the shade, you'll likely be disappointed.

• Drought during late summer or early frosts in spring can affect the formation of buds or cause them to die off. To prevent these issues, make sure your wisteria is sheltered from cold winds and water it regularly during dry spells in late summer.

Wisteria scale is a rare problem that can affect plants grown in London. The sap-sucking insects can be spotted in late spring on wisteria stems. It looks like a dark brown hemispherical shell, up to a centimeter in diameter. Large populations can cause stems to die back. Wisteria can get scale infestations from other bugs, but these don't tend to be as damaging.

If you notice brown blotches on the leaves of your wisteria, this could be a sign of powdery mildew. Plants are more at risk during drought, and watering your wisteria during dry spells can help prevent the issue.

 

Our favourite wisteria varieties

Wisteria sinensis 'Prolific' lives up to its name, producing masses of highly fragrant lilac-blue flowers in late spring and early summer. It has an RHS Award of Garden Merit for its reliability and performance.

Wisteria floribunda 'Alba' is a white wisteria with 60 cm long racemes of lilac-tinged white flowers. This is a grafted variety, meaning it will flower earlier than plants grown from seed.

Wisteria floribunda 'Violacea Plena' stands out amongst wisterias with deep purple, fully double flowers. Due to their shape, the flowers aren't as attractive to pollinators, but they last longer on the vine.

Wisteria floribunda 'Rosea' is another RHS-recommended cultivar. This attractive pink wisteria blooms in May and June and is slower-growing than other varieties.

 

FAQ

How do you grow wisteria?

You need a sunny, sheltered spot to grow wisteria with a sturdy support structure for the vine to grow up, such as a pergola or wall. Keep your wisteria well watered while it establishes and feed it in spring with rose feed or another high-potassium fertiliser. Wisterias need training and pruning twice a year.

When does wisteria bloom?

Most wisteria bloom in late spring and early summer, in April, May or June. Chinese wisteria (Wisteria sinensis) flowers earlier than Japanese wisteria (Wisteria floribunda).

Can you grow wisteria in a pot?

You can grow wisteria in a pot as long as you select an appropriate variety and you're prepared to spend time looking after it. Standard forms, which are pruned to maintain a compact size, are the best option for growing in pots. Choose a large pot and feed and water your wisteria regularly.

How long does wisteria take to grow?

Wisteria is fast-growing once established, and some varieties can grow up to three metres in a year. Twice-annual pruning is essential to keep on top of new shoots and encourage the plant to produce flower buds. Although they grow quickly, young wisteria plants can take several years to flower.