A small deciduous shrub from Japan, the Nippon Spirea ‘Snowbound’ covers its branches and leaves so thickly in spring with clusters of small white flowers that it looks as if it is coated with snow. The dark green leaves appear after flowering starts, often with their tips showing through the flower clusters. While young, the shrub is upright and vase-shaped but soon the stems arch and from then on ‘Snowbank’ resembles a fountain.
This cultivar grows and flowers best in full sun but tolerates partial shade. It prefers well-drained, moist soil but is adaptable to many soils, as well as heat, drought, and heavy pruning. In winter, remove the dried flower stalks which, if left through the next growing season, make the shrub look untidy. This shrub makes a good feature plant and works well in groups, informal hedges and borders, or at entranceways and foundations.
Plant in spring or fall. Space plants 2 to 15 feet apart, depending on the expected mature size of the plant. Dig a hole only as deep as the root ball and 2 to 3 times as wide. If your soil is in very poor condition, amend the soil you’ve removed from the hole with a small amount of compost. Otherwise don’t amend it at all. Carefully remove the plant from the container and set it in the hole. Fill in around the root ball with soil until the hole is about half filled. Then firm the soil and water thoroughly. Fill the hole with the remaining soil and water again. Form a raised ridge of soil around the perimeter of the hole so it acts like a berm to help hold in water.
Apply a layer of compost under the tree each spring, spreading it out to the dripline (the area under the outermost branches). Add a 2-inch layer of mulch to retain moisture and control weeds. Water plants during the summer if rainfall is less than 1 inch per week. Deadheading spent flowers will sometimes induce a second flowering. Most spireas can be pruned after flowering to reduce height and maintain the desired shape. However, Japanese and bumald spireas should be pruned in early spring to promote the best flowering. Remove dead, diseased, and broken branches anytime. Spireas can be severely pruned and will grow and flower again.
Winchester Gardens generally stocks this item.