Learn About The Incredible Growth Rate Of Wisteria

Wisteria is a beautiful flowering vine that produces grape-like clusters of lilac, bluish, or occasionally white blooms. If you have seen these sprawling vines with spring and summer flowers climbing an arbor, trellis, or porch and been tempted to get one for your garden, beware. Fast-growing wisteria vines are common, and can be a real problem.

Is Wisteria Invasive?

There are several types of wisteria we see in American gardens. Some are native, but many of the common vines found in garden centers are not native. The most common types are Japanese (Wisteria floribunda) and Chinese wisteria (Wisteria sinensis).

Both of these Asian wisterias are considered invasive in many areas. Check with your local extension office for information regarding your region or state. There are pros and cons of growing wisteria, but in North America, wisteria is labeled as invasive because of how fast it grows and its tendency to choke out other plants. It can also girdle trees and kill them.

How Fast Do Wisteria Vines Grow?

Non-native wisteria growth rate is extremely fast. These vines can grow as much as ten feet (3 m) in one year. This is the primary problem with Asian wisterias and why they are considered invasive in many areas. Any non-native plant that grows so quickly can limit the growth of or even kill native species.

Another issue is that out-of-control growth can damage structures. If not pruned regularly and aggressively, wisteria can grow up the side of a house, causing damage to the siding and roof.

How Long Does Wisteria Take to Grow to Full Size?

Wisteria vines can easily grow up to 30 to 40 feet (9 to 12 m) with vines as big as 15 inches (38 cm) in diameter, so controlling wisteria vines is important. Asian wisteria species are also very long-lived, up to 50 years. With 10 feet (3 m) of growth per year, you can have a full-size vine within just a few years.

Native Alternatives to Invasive Wisteria

Because of its invasive nature and high maintenance needs, many gardeners are rethinking Chinese wisteria. A good alternative is Wisteria frutescens. Also known as Texas or American wisteria, this native species grows throughout the eastern U.S. and is hardy to zone 5.

Native wisteria can reach impressive heights of 30 feet (9 m) like invasive wisteria, but it will do so much more slowly. This makes it a good choice for anyone worried about harming other plants or the high pruning needs of Chinese wisteria.

There are some other differences between Texas and Asian wisteria:

• While the Asian species flower first, native wisteria leafs out first and then blooms.
• The flower clusters (racemes) on Texas wisteria are rounder and more compact. The Asian racemes are longer.
• Native flower racemes are 3 to 6 inches (7.6 to 15.2 cm) while the Asian racemes can be up to 12 inches (30.5 cm) long.
• Both species are legumes that produce seed pods. On Asian species, the pods are fuzzy, while the native seed pods are smooth.

A slightly smaller option is Kentucky wisteria (Wisteria macrostachya). It grows between 15 and 25 feet (4.5 to 7.6 meters) but has flower clusters that are larger than those on the Texas wisteria.

Another benefit of the native species is that they begin to flower much sooner. You can probably find a transplant that is already blooming, while the non-native species might take several years to produce any flowers.

Growing Wisteria

Whichever type of wisteria you choose, they need full sun for optimal flowering. They do best in soil that is moist but not soggy, rich and humusy, and slightly acidic.

All wisteria types need something to grow on and support their vines or training. One solution to managing an unruly non-native species is to train it to grow as a tree far from buildings or other plants. Use a metal pole to support a single strong vine and prune it once or more a year to look like a weeping tree.

All species also need regular pruning to maintain the size and shape of the vine. Native species need much less vigorous pruning. With the Asian wisteria, plan to prune twice a year to keep it in check.

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