PSC 2620: Woody Trees and ShrubCourse HomeWeek 2

Spiraea japonica - Japanese Spirea

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Corymbs of small flowers are held approximately 2-4 inches above the foliage. Leaves are lanceolate and serrated. They are smaller than leaves on Spiraea x bumalda.

Plant Description

A small, compact shrub (2-3 feet tall and wide) with generally smaller leaves and finer texture than other species of Spiraea. Most cultivars have generally rounded form that requires little maintenance to keep. Prefers full sun, but will perform well in shade, though flower production may lessen. Requires regular watering or the leaves will burn quickly.

Dark green serrated leaves (1-2 inches) are arranged alternately on the stem. Large clusters of pink flower corymbs appear in the late spring. Once the blossoms are spent, the brown corymbs covering the plant are quite unsightly and should be pruned.

Landscape Use

Perfect for foundation plantings and as flowering accent shrubs in planting beds and borders. Can be used as informal ornamental low hedges. Good for parking lot islands because the small size will not obstruct a driver's view.

Points of interest

Although very hardy, Spiraea japonica is susceptible to ornamental damage from leaf spot and powdery mildew.

Notable Cultivars

Alpina: Small leaved variety (3/4 inch long) with dark green, slightly serrated leaves, and clusters of light pink and white flowers. Short and spread, 1-2 feet tall, 3-4 feet wide.


Little Princess: Small leaved variety (3/4 inch long) with rich green leaves. The plant is slightly larger than most other cultivars of S. japonica at nearly 3 feet. Blossoms are a pale pink.


Shirobana: A very large cultivar of S. japonica at nearly 4 feet high at maturity. It is unique for its clusters of dark pink, light pink and white blossoms can appear on the bush, though this is inconsistent between plants and many plants do not exhibit this attribute.


Magic Carpet: A beautiful dwarf form (18-24 inches) with vibrant leaf coloration. Leaves emerge dark red and slowly fade to orange, then yellow and finally to a light green. Blossoms are pink.