Japanese Tree Lilac Plant Care

Japanese Tree Lilac (Syringa reticulata subsp. amurensis) belongs to the Oleaceae family within the Syringa genus. Japanese Tree Lilac is also known as Amur Lilac.

Japanese Tree Lilac displays a deciduous shrub or small tree growth habit, reaching up to 10 ft tall with a spread of approximately 8 ft. Japanese Tree Lilac produces fragrant clusters of tubular flowers in various colors.

Leaf size: approximately 4 inches.

Water a young or newly planted Japanese Tree Lilac 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 Tree Lilac thrives in full sun to partial shade.

Syringa reticulata subsp. amurensis tolerates temperatures of 0–90°F. Japanese Tree Lilac prefers humidity levels of 40–70%.

Well-draining, fertile soil with a slightly acidic pH. Good drainage is essential for Japanese Tree Lilac to prevent waterlogging, which leads to root rot and fungal issues.

Feed Japanese Tree Lilac 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, fertile soil with a slightly acidic pH. Avoid low spots where water collects after rain.

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 Tree Lilac can spread to about 8 ft (2.4 m) and reach about 10 ft (3 m) tall. Space plants about 8 ft (2.4 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 Tree Lilac 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.

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 Tree Lilac can be propagated through softwood cuttings, layering. Similar propagation techniques also apply to japanese tree lilac plant care, which shares the same genus.

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Japanese Tree Lilac is susceptible to aphids, powdery mildew. 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.