1 / 15

Salix spp.

willows

Northern Hemisphere (cold-temperate and arctic Asia, Europe, and North America), with some species in South America and southern Africa

Attracts Pollinators Attracts Butterflies

Native to North America

SunFull Sun – Part Shade

WaterHigh

HardinessZones 2–9

Overview

Salix spp. is a genus of deciduous trees and shrubs in the Salicaceae family, containing roughly 350 species concentrated in cold and temperate regions of the Northern Hemisphere, with many species growing along streams, wetlands, and other moist ground. Habit ranges from prostrate arctic shrubs a few inches tall, such as S. herbacea, to single-trunked trees reaching 100 feet (30 m), such as S. alba. Most species carry narrow, lanceolate leaves 1-6 inches (2.5-15 cm) long, green above and paler or silvery beneath, on slender, flexible twigs that root readily from cuttings. Plants are dioecious, bearing male and female catkins on separate individuals; the catkins open in early spring before or with the leaves and measure 0.5-4 inches (1-10 cm) long. Willows grow quickly, with many species adding 3-8 feet (0.9-2.4 m) per year, but the soft wood is brittle and branches break in wind and ice. Water-seeking roots invade drains and septic systems, and most species are short-lived compared with hardwoods, declining after 30-50 years. The genus supports many insects and serves as a larval host for several butterfly and moth species. Salix spp. bark contains salicin, the compound from which salicylic acid takes its name.

Native Range

Salix spp. occurs throughout the Northern Hemisphere, with the greatest species diversity in cold-temperate and arctic Asia, Europe, and North America. A smaller number of species extend into the Southern Hemisphere in South America and southern Africa.

Suggested Uses

Used in streambank stabilization, erosion control, and wet-soil plantings where the dense roots bind soil. Larger species are grown as shade and specimen trees, while shrubby species are coppiced for basketry, biomass, and living fences. Early catkins are a pollen and nectar source for bees.

How to Identify

Identify Salix spp. by slender, flexible twigs bearing a single bud scale at each node and narrow, often lanceolate leaves with finely toothed margins. Catkins appear in early spring, upright and cylindrical, with male and female forms on separate plants. Bark is smooth and greenish on young stems, becoming furrowed and gray with age. The single bud scale separates willows from poplars (Populus spp.), which carry several overlapping bud scales.

Appearance

Size & Dimensions

Height2" - 100'

Width/Spread1' - 50'

Reaches mature size in approximately 10 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring

Catkins open in early spring, typically March to May depending on latitude and elevation, usually before or as the leaves expand. Male catkins shed yellow pollen while female catkins are greener and develop into seed capsules. Bloom on an individual plant lasts about 2-3 weeks. The wind- and insect-pollinated flowers release seeds with cottony tufts in late spring.

Detailed Descriptions

Flower Description

yellow to silver-green

Foliage Description

green to silver-green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

clay loam sand silt

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

rapid; many species add 3-8 feet (0.9-2.4 m) per year

Care & Maintenance

Care Guide

Plants in this genus grow in full sun and prefer consistently moist to wet soils, tolerating seasonal flooding that kills many other woody plants. They adapt to clay, loam, sand, and silt across soil pH 5.5-7.5 but decline in dry, compacted ground. Most species root easily from dormant hardwood cuttings pushed directly into moist soil. Growth is rapid, so plants establish within a few seasons, though the brittle wood breaks in storms when plants stand near structures and overhead lines. Common problems include canker, willow scab, aphids, and borers. Hardiness spans USDA zones 2-9 depending on species.

Pruning

Prune in late winter while dormant to remove broken, crossing, or dead wood. Species grown as coppice or pollard are cut back hard every 1-3 years to produce straight young stems. Cutting stimulates vigorous regrowth from the stump or pollard head.