Willows are among the easiest trees to grow and among the more demanding to keep in good shape. They root readily, tolerate wet ground and grow quickly, but the same fast growth gives them weak wood and aggressive roots. Good willow care is mostly about four things: the right site, steady moisture, regular pruning and keeping an eye on pests.

Table of Contents

The short answer: give a willow full sun or part shade, moist soil and plenty of room away from pipes and buildings. Water deeply in dry spells, especially while young, and keep a 3 to 4 inch mulch ring off the trunk. Train young trees to one strong trunk and remove dead, broken or crossing branches every year during dormancy. Watch for willow leaf beetles, aphids and cankers.

1. Choose the right site

Most willow problems start with the planting spot. NC State Extension says weeping willow grows best in full sun or partial shade and very moist soils, from acidic to alkaline. The Morton Arboretum notes that willows are very tolerant of wet sites.

Space is the other requirement. University of Florida IFAS Extension says weeping willow reaches 30 to 50 feet tall with an equal or greater spread, and that its roots can extend about three times the radius of the canopy. It recommends keeping the tree away from sewer and septic lines. Our guide to how big a weeping willow gets has the full size figures.

Good willow sites include pond edges, low wet corners of large yards and stream banks. Poor sites include small yards, spots near foundations and anywhere above water or sewer pipes.

2. Keep the soil moist

Willows are thirsty. UF/IFAS notes that weeping willow will survive drought but loses some leaves without irrigation. A willow in a wet site rarely needs help; one in an ordinary lawn will need water in dry spells.

Follow The Morton Arboretum’s general rule: check the soil before watering rather than following a schedule, and when it is dry an inch or two down, water deeply enough to wet the soil 5 to 6 inches. About an inch of water applied at once reaches that depth. Young willows need this most during their first few seasons.

3. Mulch the root zone

Mulch holds moisture and protects roots from mowers. The Morton Arboretum recommends 3 to 4 inches of medium- to coarse-textured mulch under trees, pulled back from the trunk to leave a donut-hole. Spread it as wide as practical, at least to the edge of the young tree’s canopy.

4. Prune every year

Willows need more pruning than most trees. The Morton Arboretum says black willow’s wood “is brittle and the tree may require regular pruning,” and describes white willow as fast-growing “with weak wood that is prone to storm damage.” NC State adds that weeping willow’s rapid growth produces weak wood that cracks or breaks easily, especially under snow or ice.

A yearly routine:

When: The Morton Arboretum says the best time to prune most deciduous trees is from late fall, after leaf drop, through very early spring. Dead, diseased or broken branches can come off any time.
Young trees: UF/IFAS recommends early training to a single central trunk. Remove competing leaders and branches with narrow, weak angles while they are small.
Mature trees: Remove dead wood, broken limbs and crossing branches, and raise low branches gradually if they block paths.

For step-by-step cuts and how much to remove, see our guide to pruning a weeping willow.

5. Check after storms

Because the wood breaks easily, especially under snow and ice (NC State), look over a willow after every major storm. Remove broken or hanging limbs promptly, since a hanging limb can fall without warning.

6. Watch for pests and diseases

NC State lists several common insects on weeping willow, including imported willow leaf beetle, giant willow aphid and willow bladdergall mite.

Virginia Cooperative Extension describes the imported willow leaf beetle as a defoliating pest of willows, poplars and cottonwoods. Adults overwinter under loose bark or in leaf litter, emerge in early spring to chew holes in new leaves, and lay clusters of yellow eggs on leaf undersides in May. Checking the undersides of leaves in late spring is the easiest way to catch an infestation early.

Willow twig blight, also called scab, is a common disease. Washington State University says it first infects new foliage in spring, causing dark spots along the leaf midrib, and is spread by splashing water and favored by wet weather. Its recommended controls are cultural: avoid overhead watering, prune to improve air circulation, and rake and destroy fallen leaves before the spring infection period.

7. Go easy on fertilizer

Willows grow fast on their own. The Morton Arboretum recommends adding nutrients only when a soil or foliage test shows a deficiency, and warns that excess nitrogen produces fast, soft growth that is more prone to fungal disease. For a willow, that is more weak wood to prune.

8. Plan for a short life

Willows are not long-lived trees. UF/IFAS describes weeping willow as usually short-lived, to about 30 years or so, and The Morton Arboretum says black willow may live only 40 or 50 years. Steady care helps a willow reach the upper end of its range. Our article on how long a willow tree lives covers what affects lifespan.

Willow care calendar

Season	Task
Late winter	Structural pruning; remove dead and crossing branches
Spring	Refresh mulch once soil warms; check for new pests
Summer	Water deeply in dry spells; watch for beetles and aphids
Fall	Clean up litter; water if dry before the ground freezes
After storms	Check for broken or hanging limbs

The bottom line

A willow is easy to keep alive and harder to keep tidy and safe. Plant it in moist soil with lots of room, water deeply in dry weather, mulch the root zone, prune every dormant season and check regularly for pests and storm damage.

Sources

Salix babylonica: Weeping Willow (ENH-734/ST576), University of Florida IFAS Extension
Salix babylonica, North Carolina Extension Gardener Plant Toolbox
Black Willow, The Morton Arboretum
White Willow, The Morton Arboretum
Pruning Trees, The Morton Arboretum
Imported Willow Leaf Beetle (ENTO-139), Virginia Cooperative Extension
Willow: Twig Blight (Venturia), Washington State University Hortsense
How and When to Use Fertilizer on Plants, The Morton Arboretum
How to Mulch Trees and Shrubs, The Morton Arboretum
Watering Trees and Shrubs, The Morton Arboretum

Top photo: Hans-Jürgen Neubert, CC BY 4.0, via Wikimedia Commons

Willow Tree Care: Water, Pruning, Space and Pests