The white willow (Salix alba) comprises a plethora of cultivated varieties, many of which are recognized as the weeping willow trees. White willows are fast-growing, moisture-loving trees with vigorous, spreading root systems that can extend well beyond the canopy perimeter. The white willow tree can reach 50 feet in height and width, growing more than 1 ½ feet each year. This deciduous tree can grow in nearly any climate, growing in USDA hardiness zones 2 through 8 and withstanding winter temperatures as cold as -45 degrees F.
Select a planting site that's in full to partial sunlight and has loose, moist, fertile soil. Plant your white willow tree in the fall, at least six weeks before the first expected frost.
Dig a planting hole that's twice the width and depth of the willow tree's root ball. Loosen the soil with your shovel and mix in some peat moss or organic compost if your soil is compacted or nutrient-poor.
Set the white willow tree's root ball into the planting hole with the tree standing straight up. Backfill the planting hole to fill in the soil around the roots and remove any air pockets. Plant the willow tree with the root collar, which is the point at which the root ball meets the trunk, at the ground level.
Spread a 3-inch layer of bark mulch in a 2- to 3-foot circle around the base of the white willow tree. Keep the mulch about 1 or 2 inches away from the trunk.
Water your white willow deeply and thoroughly once each week during the first year in the fall, spring and summer, soaking the soil down to and around the roots. After the first year, water your white willow tree from spring until summer during prolonged dry spells or droughts.