Burning bush

Burning bush: how do you recognise it?

Habit

Sturdy, upright clump 80 cm tall and 60 cm wide, with a somewhat woody base.

Leaves

Pinnate, with glossy dark green, leathery leaflets, like those of ash.

Flower

Spikes of five-petalled flowers with long stamens, white or lilac-pink with dark veins, in June and July.

Scent

A strong lemon scent from oil glands on the leaves, flower stems and seed capsules.

Roots

Deep, woody and branched; they dislike being moved.

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

Why grow it?

• A long-lived perennial that can stay in the same spot for decades.
• Striking flower spikes in June and July, in white or lilac-pink.
• The whole plant smells of lemon on warm days.
• Bees and bumblebees visit the flowers.
• Attractive star-shaped seed capsules after flowering.
• Once established, it copes well with drought.

Burning bush: where does it grow best?

• Full sun; in shade it hardly flowers.
• Free-draining sandy or loamy soil, neutral to chalky.
• Dry to moist; no wet soil.
• Allow 60 cm of space, in a spot where it can stay undisturbed for years.
• Not beside a path or play area, because of the irritant sap.

Light

Sun

Soil type

Sand or loam

Acidity

Neutral or chalky

Moisture

Dry or normal

Size

0.8 m tall, 0.6 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Peony: Also slow and long-lived, flowering just before it in the same sunny spot.
• Bearded iris: Also likes a sunny, dry spot on chalky soil.
• Catmint: A low blue edging in front.
• Woodland sage: Dark blue spikes beside the white or pink flowers.
• Ornamental grasses: They add movement next to the stiff clump.

Burning bush: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October; young potted plants establish best.
2. Dig a deep hole and loosen the subsoil.
3. On heavier soil, mix in some coarse sand or gravel for good drainage.
4. Set the plant at the same depth as in its pot and firm the soil; leave 60 cm between plants.
5. Water straight away and again in dry spells during the first year.
6. Wear gloves and long sleeves when planting.

Care

Water

Water in dry spells in the first year; after that it is rarely needed.

Feeding

A thin layer of compost in spring; no more is needed.

Support

Not needed: the stems are sturdy.

Patience

It grows slowly: in the first years after planting it flowers only a little.

Leave alone

Do not move or divide it: it recovers very poorly.

Tip: Give it a permanent, sunny spot straight away and plenty of patience: it grows slowly, but after a few years it flowers more each year and can live for decades.

Burning bush: when to prune it?

Pruning months: March and October.

When: It needs hardly any pruning. Cut away the dead stems in October or in March.

How:

• Leave the star-shaped seed capsules after flowering: they are decorative.
• In October or March cut the dead stems back to just above the ground.
• Work with gloves and long sleeves, preferably on a cloudy day.

Caution: Together with sunlight, the sap and oil cause skin burns: wear gloves and prune in cloudy weather.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Outdoors in September–October: sow fresh seed 1–2 cm deep in a pot or seedbed. It needs winter cold and germinates in spring, sometimes only a year later. Seedlings take 3–4 years to flower.

Division

Not recommended: the deep, woody roots divide poorly and the plant recovers badly.

Burning bush: how does it get through the winter?

Hardy to −35 °C.

• Very hardy, to about −35 °C: no protection is needed in Belgium.
• The top growth dies back; it reshoots in spring.
• Wet feet in winter can make the roots rot: choose free-draining soil.

Diseases and pests

• Skin burns: Red patches and blisters after contact on a sunny day. Wear gloves and long sleeves and rinse the skin with water straight after contact.
• Slow start: Little growth and few flowers in the first years. Be patient: after a few years it gains strength.
• Root rot: The plant declines on wet, heavy soil. Make sure of good drainage at planting time.
• Slugs: They eat the young shoots in April. Pick them off in the evening.

Through the year

• March: Cut away old stems wearing gloves. Plant. Add compost.
• April: The shoots appear. Plant. Watch for slugs.
• May: Flower buds. Water young plants in dry spells.
• June: Flowering begins. Lemon scent on warm days.
• July: Flowering. Bees and bumblebees on the flowers.
• August: The star-shaped capsules ripen.
• September: Sow fresh seed outdoors. Plant.
• October: Sow. Plant. Cut away dead stems.
• December: Rest.

Edible and useful

Not edible. The sap and fragrant oil of burning bush (gas plant) make the skin hypersensitive to sunlight: touching the flowers, seed pods or leaves on a sunny day can bring out red patches and painful blisters a day or two later, which often leave brown marks for months. Children who pick the flowers or play around the plant are most at risk. Wear gloves and long sleeves, even when cutting flowers for a vase, work on a cloudy day or in the evening, and do not plant it beside a path or where children play. If sap gets on your skin, wash it off at once with soap and water and keep that spot out of the sun for a few days. The plant is also poisonous if swallowed: keep children, dogs and cats away from it. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• On a warm, still evening the vapour of the essential oil above the flowers can sometimes flare up briefly when a match is held near it, without harming the plant: hence the names burning bush and gas plant.
• The Dutch and French names refer to the leaves, which resemble those of ash (Fraxinus).
• An established plant can go on flowering in the same spot for decades.