How to Grow Wisteria – Bob Vila

Wisteria, with its racemes of usually purple flowers, is often identified with the South. However, hardy wisteria cultivars like ‘Blue Moon’ can grow as far north as USDA zones 3 or 4, although late frosts can freeze flower buds there.

Of course, advice on growing wisteria would not be complete without a warning that it is a vigorous vine that can grow 10 feet or more per year and should therefore be kept where it cannot strangle other garden plants. Whenever possible, choose native species of wisteria over Chinese wisteria, as the latter are particularly invasive and are listed as a “noxious weed” in some states.

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Growing wisteria at a glance

common names: wisteria
Scientific name: Wisteria spp.
hardening zone: Varies by species
floor: Slightly acidic, moderately fertile, drains well
light: Full to partial sun
water: Middle
meal: Fertilizer with high phosphorus content
propagation: Stratification, cuttings or seeds
security: Poisonous

Wisteria Properties

Climbing wisteria vines can grow 20 to 100 feet in length — or as far as they are allowed to spread — and survive for 50 years or more. In spring or early summer they produce pinnate leaves and racemes of pea-like flowers. Wisteria colors are most commonly shades of purple, but they can also be white, pink, or red. Their scent has been compared to that of grape gum.

Chinese wisteria flowers appear in mid to late spring before the vine sprout, while Japanese and Native American species wait to perform until late spring to early summer when leaves also appear. In Chinese cultivars, all flowers in a raceme open immediately, while in most other cultivars, they open gradually, beginning with a wisteria blossom at the top of the raceme. Vines of Japanese varieties twine around supports in a clockwise direction, while most other types of wisteria grow counter-clockwise.

Recommended varieties of wisteria

• American wisteria (Wisteria frutescens): This native cultivar grows to 30 feet in length and is a larval plant host for skipper butterflies in USDA zones 5 through 9. Varieties such as ‘Amethyst Falls’ produce clusters of flowers up to 5 inches long.
• Chinese wisteria (Wisteria sinensis): Once the most commonly grown purple wisteria in USDA Zones 5 through 8, it is now considered overly invasive. This strain offers clusters of purple or white flowers nearly a foot long on vines that can grow to 100 feet tall if left unchecked.
• Japanese wisteria (Wisteria floribunda): This oriental cultivar can reach at least 60 feet tall in USDA zones 4 through 9 with fragrant purple, white, pink, or red flowers in 18-inch clusters.
• Kentucky Wisteria (Wisteria macrostachya): This US native wisteria is the hardiest species, growing to 25 feet tall with flower clusters up to 12 inches long in USDA Zones 3 through 9, with some cultivars—like ‘Blue Moon’—offering repeat flowering.
• Silky Wisteria (Wisteria brachybotrys): Another Japanese variety that’s easier to control than Floribunda, this white wisteria grows about 20 feet tall in USDA zones 5 through 9, with silky foliage and fragrant flowers in 4- to 6-inch racemes that appear in early summer and maybe fall again.

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plant wisteria

If possible, buy a plant that has already flowered to prove that it is mature enough to do so. Make sure it is a grafted plant or a plant grown from a cutting as seedlings can take 5 to 20 years to flower.

When is the best time to plant wisteria?

Expose a wisteria plant while it is still dormant in spring or after it is dormant in fall, and remember that planting perennials in spring is usually safest in northern zones. Be sure to choose an area with the right growing conditions for wisteria, as the plant doesn’t like being moved once it’s established.

Where can wisteria grow?

Choose a site where the soil is slightly acidic, well-draining and only moderately fertile – too much nitrogen can encourage vigorous foliage growth at the expense of flowers. The planting site should receive at least 6 hours of sunlight per day, preferably more, and contain some type of support such as an arbor, pergola roof, or horizontal wires for the wisteria to spread out about 10 feet from its base.

How do you plant wisteria?

Make sure you plant your wisteria vine where there is no chance of it escaping into the wild as it can be very invasive.

1. After giving your wisteria plant a good watering, remove it from its container.
2. Dig a hole as deep as the plant’s root ball and three times as wide as that ball near the base of a post or other vertical support.
3. If you plan to put up more than one wisteria vine, space them at least 10 feet apart.
4. Position the crown of your wisteria at the same height it grew in its container, unless it is a grafted plant, in which case the transplant should be 1 inch (2.5 cm) below the ground.

Can you grow wisteria in containers?

One of the smaller wisterias, like the American species, should be able to grow in a container as long as it has some sort of trellis to support the wisteria in or near the container. However, if you plan on keeping this container outside – which will likely be necessary since outdoor plants that winter dormant will not make good houseplants – your wisteria should be listed as hardy at least two zones north of your own zone to be in the To be able to survive above ground conditions.

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watering wisteria

A wisteria plant needs an average amount of water, about 1 inch per week, to thrive. If your climate doesn’t provide enough moisture for growing wisteria, you may need to provide the equivalent yourself through irrigation or a watering can.

Mulch the plant with a few inches of chopped bark so the soil always retains some moisture. However, avoid overwatering them as this encourages lush foliage growth which is thought to stunt flowering.

fertilize wisteria

Wisteria plants usually grow fast enough without additional feeding and can absorb all the nutrients they need from the soil; Plants grown in containers may need a boost. If you do need to fertilize your wisteria, only do so once a year in the spring and instead of a high-nitrogen fertilizer, use a fertilizer high in phosphorus – such as. Too much nitrogen can cause the plant to focus all of its energy on excessive foliar production, “distracting” it from flowering.

Pruning wisteria

Prune wisteria after they have finished blooming in summer. Shorten the shoots to about 6 inches so each contains only two or three buds.

To turn a wisteria vine into a tree, plant it next to a stake and train a single shoot up the stake as a trunk, removing all other shoots. The following year, cut off the top of the trunk at the top of the stake to force the tree to branch there. Such wisteria trees need constant shaping.

Propagation of wisteria

A mature wisteria vine roots wherever it touches the ground. So the easiest way to get a new plant is to pin a sprout onto a bare patch of soil in a process called stratification.

When considering how to grow wisteria from seed, remember that it typically takes 5 to 20 years for a seedling to grow into a flowering vine. If you still want to try germination, soak the seeds overnight before sowing them ½ inch deep. Keep your container around 60 degrees Fahrenheit until you see sprouts, which often takes 30 days or more.

safety aspects

Make sure the wisteria structures you grow your vines on, like pergolas or canopies, have strong supports. The vines can get very heavy over the years, allowing them to bend posts that aren’t strong enough to support all that weight.

These vines are also poisonous to humans, pets, and horses. The seed pods and seeds, which make a popping noise when opened, are reportedly the most toxic part of wisteria. So it’s a good idea to remove these as soon as they appear so children aren’t tempted to try the “beans”.

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Possible pests and diseases

Because wisteria is such a vigorous vine, it rarely suffers from pests and diseases, so its most complained-of problem is sterility, a refusal to bear flowers. This is most common with Chinese wisteria, as they take longer to mature than native varieties.

If a wisteria isn’t performing even after the above fertilizing and pruning, try a fall root pruning. To do this, use a shovel to “draw” a circle a few feet from the trunk of the vine, then dip the blade of the shovel into the soil at least 10 inches around the perimeter of that circle. Pruning the roots causes the plant to go into survival mode and increases flower (and therefore seed) production.

Prepare wisteria for winter

If you garden in a northern state, planting a wisteria against a building wall is a good idea. This is actually not to protect the plant, which normally survives the winter without any problems if it has enough mulch, but to protect its flower buds from late spring frosts. However, be careful not to let the vines work their way under the trim.

If your wisteria is growing in a pot, after the plant is dormant in the fall, place the pot in an unheated shed or garage for the winter, making sure the soil remains moist during that time.

Looking for more vine plants? Check out our articles on growing flowering climbing plants, climbing plants and climbing vegetables.