Japanese Spirea Plant Care

Japanese Spirea (Spiraea incisa) belongs to the Rosaceae family within the Spiraea genus. Japanese Spirea is native to eastern Asia. Japanese Spirea is also known as Angular Japanese Spirea, Cutleaf Japanese Spirea, Spirea.

Japanese Spirea displays an upright, spreading shrub growth habit, reaching up to 5 ft tall with a spread of approximately 6 ft. Japanese Spirea produces clusters of small white, pink, or red flowers.

Leaf size: approximately 3 inches.

Water a young or newly planted Japanese Spirea every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Japanese Spirea thrives in full sun to partial shade.

Spiraea incisa tolerates temperatures of 50–90°F. Japanese Spirea prefers humidity levels of 40–70%.

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Japanese Spirea to prevent waterlogging, which leads to root rot and fungal issues.

Feed Japanese Spirea every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining loamy soil with added compost for nutrients. Avoid low spots where water collects after rain.

Japanese Spirea is suited to USDA Zone 5a – 7b.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Japanese Spirea can spread to about 6 ft (1.8 m) and reach about 5 ft (2 m) tall. Space plants about 6 ft (1.8 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Japanese Spirea while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Japanese Spirea is hardy down to USDA zone 5a, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.

Japanese Spirea can be propagated through softwood cuttings, division of roots, seeds. Similar propagation techniques also apply to bridal wreath spirea plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Japanese Spirea is susceptible to aphids, spider mites, leaf rollers. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Japanese Spirea grows outdoors in USDA Zone 5a – 7b. It survives winters down to planting zone 5a. Japanese Spirea is native to eastern Asia.