Hungarian lilac

Hungarian lilac: how do you recognise it?

Habit

Sturdy, upright, multi-stemmed shrub about 3 m tall and wide.

Leaves

Elliptic, 6–12 cm, opposite; glossy dark green above, paler beneath.

Flowers

Upright panicles of dark lilac flowers, in June.

Scent

Soft and sweet, less heavy than in common lilac.

Roots

Fibrous and branching; it may form some suckers.

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

Why grow it?

• Late flowering in June, when common lilacs have finished.
• Dark lilac panicles, lovely in the garden and in a vase.
• Tolerates damper soil better than common lilac.
• Very hardy and tough, even in an open position.
• Bees and butterflies visit the flowers.

Hungarian lilac: where does it grow best?

• Sun to partial shade; it flowers best in sun.
• Rich soil: sand, loam or clay, best neutral to chalky; add a little lime on acid soil.
• Normally moist to damp soil; it copes better with damp spots than common lilac, but not with permanently wet feet.
• A spot near a terrace or window where you will smell it, or a loose hedge in the damp corner.
• 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 or wet

Size

3 m tall, 3 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Siberian iris: Tolerates damp soil and flowers at the same time, in blue and purple.
• Meadowsweet: Cloudy, cream-white plumes for a damp spot.
• Guelder rose: Also likes damp soil and gives flowers and berries.
• Peony: Flowers at the same time in May–June and fills the space in front of the shrub.

Hungarian 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; in a damp corner usually completely.

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 moist and suppresses weeds.

Spent flowers

Cut off the faded panicles straight after flowering; this keeps the shrub tidy.

Liming

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

Tip: A good lilac for the awkward, slightly damp corner where common lilac will not grow. It copes better with damp soil, but not with permanently wet feet.

Hungarian lilac: when to prune it?

Pruning months: June–July.

When: Straight after flowering, in June–July.

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.
• A shrub that is too tall or bare can be shortened by a third after flowering.
• Every few years, take a few of the oldest stems to the ground to keep the shrub young.

Caution: Lilacs flower on old wood: the flower buds form in summer. So never prune in winter or spring, nor after mid-July, or you will cut off the flowers.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow fresh seed in autumn in pots left outdoors; it needs a cold spell and germinates in spring. The seedlings flower after a few years.

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.

Hungarian lilac: how does it get through the winter?

Hardy to −35 °C.

• Very hardy, down to about −35 °C: in Belgium it never needs protection.
• Next year’s buds 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 too late. Move it to a sunnier spot, feed less and prune only after flowering.
• Root rot: Yellow, limp leaves and dying branches where water stands. Improve the drainage or move it to a better-drained spot.

Through the year

• March: Plant or transplant. Give compost.
• April: Apply mulch. Water young plants.
• May: Buds swell. Watch for aphids.
• June: Flowering. Cut off faded panicles. Prune after flowering.
• July: Take softwood cuttings. No more pruning after mid-July.
• August: Watch for powdery mildew. Water in dry weather.
• October: Plant. Sow fresh seed.
• 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?

• The species name josikaea honours Baroness Rosalia von Josika, who discovered the shrub in the 19th century.
• Crossed with Syringa reflexa, it gave the hybrid Syringa × josiflexa.
• The flower buds form as early as the summer of the previous year and spend the winter on the branches.