How to Care for a Corkscrew Willow Tree
The corkscrew willow, so called because its branches appear contorted into wavy shapes as it matures, is a highly valued, fast-growing landscape tree that has a short life.
Corkscrew willow is known by the botanical name Salix babylonica var. pekinensis ‘Tortuosa’, but some sites still refer to it under its previous species assignment, Salix matsudana. Additional common names include dragon’s claw willow, rattlesnake willow, contorted willow and curly willow. Its USDA hardiness zones include 5 to 8.
About the Corkscrew Willow
A standout landscape deciduous tree, the corkscrew willow’s twisted branches are especially visible in late fall and winter after its leaves drop to reveal the bare branches.
It has a fast growth rate with a mature height of 20 to 40 feet with a spread of about 15 to 25 feet. Its leaves are about 3 to 6 inches long and somewhat curving. It produces cylindrical flower clusters called catkins.
If you want a weeping specimen, consider the cultivar Pendula.
As this tree grows older, its branches can break at the crotch, and its weak wood can begin to splinter. It is also susceptible to disease and pests; hence, this tree has a relatively short life, like many other fast-growing trees.
Its fresh or dried stems are effective in flower arrangements.
Planting and Basic Care
The corkscrew willow needs little care once planted, but it has specific growing requirements.
Planting a Corkscrew Willow
The corkscrew willow prefers full sun and moist soil that is well-draining, although you can plant it in partial shade. It tolerates a range of soil types including clay, loam and sand, and it can grow in either acidic or alkaline soil. However, it must have moist soil; avoid overly dry areas.
Dig a hole twice the diameter of the rootball at a depth the same as the rootball, maintaining enough spacing from structures or other landscape elements to allow the tree full growth—at least 23 feet to accommodate an eventual 25-foot spread.
Place the seedling or sapling in the hole at the same level it was in its container. Backfill the hole and then water thoroughly, maintaining even moisture until it is established.
Irrigation and Fertilization
Because this tree prefers soil on the wet side, ensure regular irrigation during dry periods. Fertilize annually with a balanced fertilizer, which will help the tree withstand assaults by disease and pests.
Diseases and Pests
Unfortunately, this otherwise desirable tree is susceptible to multiple diseases and insect pests.
The best way to control diseases and pests is to rake up fallen leaves in the fall. During the growing season, a stressed willow tree is susceptible to diseases and pests. In particular, arid conditions can stress a willow, so if your area experiences very dry or hot summers, be sure to mulch the tree and irrigate.
The corkscrew willow is targeted by several diseases, including powdery mildew, tar spot, crown gall and black canker.
- Powdery mildew creates a white coating on the leaves but is usually not severe enough to affect the health of the tree.
- If you see black, raised spots on the leaves, it is probably tar spot, but this doesn’t have a severe effect on the tree either.
- Crown gall is a very serious disease and results in galls forming at the soil line. If this occurs, the tree will become girdled so that it cannot take up nutrients. The only option at that point is to remove the infected tree.
- Black canker is a fungus that results in black leaf spots. Leaves will eventually wilt, and then the stem will develop a black canker. This can result in girdling and dead branches. While you can prune off the branches, any remaining tissue with canker will not expand with the growing branches, and a crack will form. Fungicides have not been proven to be effective against this disease, but a healthy tree may be able to resist this fungus.
As with many trees, aphids can be a problem. You’ll notice honeydew deposits on lower leaves. Usually, no action is necessary because predatory insects often control aphids.
This tree can also be targeted by the gypsy moth. A serious infestation of this pest can defoliate a tree, as the caterpillars are voracious eaters. You can hose off egg masses or, if the infestation is severe, use the bacterium Bacillus thuringiensis 'Kurstaki' (Btk).
If the leaves appear mottled and yellow, lace bugs might be the culprit. These insects feed on the underside of leaves, where you might see small, dark droppings. Usually, healthy trees can fend off these bugs. If the damage becomes severe, hose them off with a strong spray of water or apply insecticidal soap or horticultural oil to the undersides of the leaves.
- Missouri Botanical Garden: Salix babylonica var. pekinensis 'Tortuosa'
- NC State Extension: Salix babylonica var. tortuosa
- University of Florida IFAS Extension: Salix matsudana ‘Tortuosa’: Corkscrew Willow
- University of Illinois Extension: Grow Curly Willows for an Artistic Twist in the Landscape
- University of Illinois Extension: Gypsy Moth
- Texas A&M: Crown Gall on Willows
- Purdue University: Black Canker of Willow
- When selecting a planting location for the corkscrew willow tree, keep in mind that it's a short-lived tree with aggressive roots and potentially destructive surface roots. Plant the corkscrew willow in a moist location and away from underground utilities, sidewalks, driveways, patios or septic systems for best results.
- Beware of diseases like crown gall, willow scab, black canker and other various fungal or foliar diseases infecting your corkscrew willow tree. Prune away all infected branches, rake up and discard any diseased fallen leaves, and apply an appropriate fungicide to the tree according to the directions on the label.
I garden in the Pacific North west, previously Hawaii where I had an avocado orchard. I have a Master Gardeners certificate here in Eugene, Oregon.