Chinese lilac

Chinese lilac: how do you recognise it?

Habit

Wide, arching shrub about 3 m tall and wide, with a loose, graceful structure.

Leaves

Oval to lance-shaped, 4–8 cm, opposite, dark green; smaller and narrower than in common lilac.

Flowers

Loose, drooping panicles of lilac-purple flowers, in May.

Scent

Sweet and full, especially on warm days.

Roots

Fibrous and branching; it may form some suckers.

Flowering: May · Plants: March–April and October–November · Pruning: May–June

Why grow it?

• Abundant, scented panicles in May, lovely to cut for a vase.
• A graceful, arching shape, looser than common lilac.
• Bees and butterflies visit the flowers.
• Fully hardy, tough and long-lived in the garden.
• Works as a loose hedge or as a free-standing shrub.

Chinese lilac: where does it grow best?

• Sun to partial shade; the sunnier the spot, the richer the flowering.
• Rich, well-drained soil: sand, loam or clay, preferably neutral to chalky; add a little lime on acid soil.
• Normally moist soil; it dislikes wet feet.
• A spot near a terrace or window, where you can smell it, gives the most pleasure.
• Allow 2.5–3 m of space per plant.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

3 m tall, 3 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Peony: Flowers at the same time in May–June and fills the space in front of the shrub.
• Cranesbill (hardy geranium): Blue or purple flowers fill the space under the shrub.
• Ornamental onion (Allium): Round purple heads go well with the lilac colour.
• Rose: An old or shrub rose flowers after the lilac and takes over the garden.
• Foxglove: Tall flower spires in May–June among the shrubs.

Chinese lilac: when and how to plant it?

Plant in March–April and October–November.

1. Plant in March–April or in October–November, when the soil is neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball and mix in compost.
3. Set the shrub at the same depth as it stood in its pot and firm the soil well.
4. Keep 2.5–3 m away from other shrubs and buildings.
5. Water in well straight away, even if it is raining.
6. Spread a layer of compost or bark around the base, without covering the stem.

Care

Water

Weekly in dry spells in the first year. After that rain is enough, except in long dry summers.

Feeding

In spring, a spadeful of compost or organic fertiliser. Too much nitrogen gives plenty of leaves and few flowers.

Mulching

A layer of compost or bark keeps the soil cool and moist.

Spent flowers

Cut off the faded panicles straight after flowering; the shrub then puts its energy into new flower buds.

Liming

On acid soil, scatter a little lime every few years.

Tip: Plant it near a terrace or under a window, where you can smell it, and cut panicles for a vase: that is already the first pruning after flowering.

Chinese lilac: when to prune it?

Pruning months: May–June.

When: Straight after flowering, in May–June.

How:

• Cut off the faded panicles just above the first pair of leaves or young shoots.
• Remove dead, weak and crossing stems right at the base.
• Every year or every few years, take a few of the oldest stems to the ground to keep the shrub young.
• An overgrown, bare shrub can be cut back hard in late spring; expect a year with few or no flowers.

Caution: Lilacs flower on old wood: the buds form the summer before. Do not prune in winter or early spring, or you will cut off the flowers.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Lifting suckers

In autumn, lift a rooted sucker and plant it elsewhere. On grafted shrubs the sucker comes from the rootstock: it is not the same as the plant.

Softwood cuttings

In June–July: 8–10 cm cuttings from young shoots in moist cutting compost under plastic. Results vary, so take several.

Layering

In spring, bury a low stem and pin it down; separate it after a year.

Chinese lilac: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, down to about −30 °C: in Belgium it never needs protection.
• The buds for next year’s flowers are already on the branches, so do not prune in winter.
• In a pot: stand it against a wall and wrap the pot in hessian so the roots do not freeze.

Diseases and pests

• Powdery mildew: White powder on the leaves from late summer. Usually harmless; ensure air and space, water at the base and thin a dense shrub.
• Bacterial blight: Black spots on leaves and young shoots and dying tips in a cool, wet spring. Cut affected wood back into healthy wood, clear the prunings and avoid too much nitrogen.
• Few or no flowers: Too much shade, too much nitrogen fertiliser or pruning in winter. Move it to a sunnier spot, feed less and prune only after flowering.
• Suckers: Young shoots appear next to the shrub. Lift them in autumn or spring; on grafted plants these come from the rootstock.

Through the year

• March: Plant or transplant. Give compost.
• April: Apply mulch. Water young plants.
• May: Flowering. Cut off faded panicles. Cut stems for a vase.
• June: Prune after flowering. Take softwood cuttings.
• July: Water in dry weather.
• August: Watch for powdery mildew. Water in dry weather.
• September: Check for suckers.
• October: Plant. Lift suckers.
• November: Plant. Clear fallen leaves.
• December: Dormant. Next year’s buds are already on the branches.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Despite the name chinensis, this lilac does not come from China: the hybrid arose in France.
• Lilacs belong to the olive family, like olive, jasmine and ash.
• The flower buds form as early as the summer of the previous year and spend the winter on the branches.