The Sandbar willow (Salix interior) is a small tree that is often shrub like and forms dense thickets on newly formed sand bars. It is the most abundant willow in Iowa and can be found throughout the state. The sandbar willow is the pioneer tree on newly formed soils along streams and has a dense, fibrous root system valuable for protecting soil against water cutting.
Habitat: Can be found growing in wet places near wooded edges, floodplains, marshes, lake shores and low-lying prairie.
Hardiness: Zone 3
Growth Rate: Moderate
Mature Shape: Medium shrub, rounded, suckers to form a thicket of wispy, slender stems
Height: 5-10 feet
Width: 5-10 feet
Site Requirements: Performs best on deep, moist loams, found along stream beds. Adaptable to moderately high pH soils. Full sun. Does well in moist sites and survives sever flooding. Not drought tolerant. Suckers profusely and not recommended for use in home landscapes.
Leaves: Alternate, simple, long and thin
Flowering Dates: Flowers in Spring as leaves first emerge
Seed Dispersal Dates: May - June
Seed Bearing Age: 10 Years
Seed Bearing Frequency: Yearly
Seed Stratification: No stratification period is needed.
The leaves are very narrow (1/4 to 3/8 inch) and pointed at both ends, and are more slender than the other willows. They are smooth, yellow-green above, pale beneath and not glossy. The leaves have widely spaced marginal teeth.
The brown buds are 1/8 inch long and sharp pointed. The twigs are slender, gray to dark orange and smooth. The fruit is a catkin with light brown capsules 1/4 inch long. The bark is smooth and light gray-brown on young stems. On trunks it is dark gray to brown and smooth or very shallow fissured.
Insects that Can Affect Sandbar Willow