Crimson bottlebrush

Crimson bottlebrush: how do you recognise it?

Habit

Evergreen, loose shrub about 2 m tall and 1.5 m wide, with a branching, slightly weeping crown.

Foliage

Narrow and lance-shaped, leathery green; young shoots are silky and reddish.

Flower

Bright red, cylindrical bottlebrushes about 10 cm long, from June to August; the colour comes from the stamens.

Fruit

Small, woody, cup-shaped capsules that stay clustered around the branch, often for years.

Roots

Fine and fibrous, sensitive to waterlogging: the soil must be free-draining and light.

Flowering: June–August · Plants: May–June · Pruning: August–September

Why grow it?

• Bright red bottlebrush flowers from June to August: a striking exotic for the terrace.
• Evergreen foliage, with young, silky, reddish shoots that add interest.
• Bees visit the nectar-rich flowers.
• Lovely in a pot, as a specimen on the terrace or in a sheltered, south-facing corner.
• Compact: about 2 m tall and 1.5 m wide, and easy to keep in check by pruning.

Crimson bottlebrush: where does it grow best?

• Full sun: only then does it flower richly; in half shade flowering stays sparse.
• Free-draining, humus-rich, acid to neutral soil or compost; no lime.
• Moderately moist: the root ball must never dry out completely during the growing season, but water must not stand.
• Sheltered from cold wind, for example against a south-facing wall or on a warm terrace.
• In the ground: 1.5 m of space; in a pot at least 30–40 cm across.

Light

Sun

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

2 m tall, 1.5 m wide

Hardiness

Half hardy (to -7 °C): protect it in harsh winters

Goes well with

• Agapanthus: Blue flower heads in summer, also in a pot on the terrace.
• Lavender: Purple flowers and fragrance, in the same warm, sunny spot.
• Olive tree: Silver-green foliage, a Mediterranean feel on the terrace.
• Rosemary: Evergreen, fragrant and bee-friendly, in a separate pot.
• Pelargonium: Red or pink flowers all summer on the terrace.

Crimson bottlebrush: when and how to plant it?

Plant in May–June.

1. Only put it outside or plant it out in May–June, when no more frost is expected.
2. Choose a pot of at least 30–40 cm with drainage holes and a layer of clay pebbles at the bottom. Use ericaceous compost (for rhododendrons) with a third sand or perlite.
3. Set the plant at the same depth as in its old pot and firm the compost.
4. In the ground: dig a hole twice as wide as the root ball, in acid or neutral, free-draining soil against a sunny, sheltered wall.
5. Water in at once, preferably with rainwater, and keep the soil moist for the first few weeks.
6. Lay a layer of acid mulch (bark or leaf mould) on the soil, keeping it clear of the stem.

Care

Water

Regularly in the growing season to keep the root ball slightly moist; preferably rainwater, as hard water gives pale leaves. Do not let water stand in the saucer.

Feeding

From May to August monthly, a feed for acid-loving plants, following the dose on the pack.

Repotting

Every 2–3 years in April–May, into a slightly larger pot with fresh ericaceous compost.

Spent flowers

The faded spikes grow on into a leafy shoot. Do not cut them back too deeply.

Terrace spot

Stand it on a sunny, sheltered terrace from May to October; first accustom it to outdoor light by putting it in half shade for a few days.

Tip: Grow it in a pot and stand it on a sunny, sheltered terrace from May to October. Overwinter it bright, cool and frost-free; in a mild area it may stay against a south wall.

Crimson bottlebrush: when to prune it?

Pruning months: August–September.

When: After flowering, in August–September.

How:

• Cut off the spent spikes with a few centimetres of green shoot.
• Shape the shrub lightly: shorten overlong shoots to just above a pair of leaves.
• Remove dead or weak branches completely.
• Leave the woody capsules or cut them off with the spikes; they are harmless.

Caution: Do not prune into old, bare wood: it often fails to regrow. Do not prune late in autumn either, as the new growth freezes easily.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In July–September: take 8–10 cm cuttings of firm, semi-ripe wood, remove the lower leaves and root in sandy, acid compost under plastic in a warm, bright spot. Rooting takes weeks to months: be patient.

Seed

Scatter the seed from the woody capsules on the surface of moist, acid seed compost at about 18–20 °C, without covering. Seedlings may differ from the parent plant.

Crimson bottlebrush: how does it get through the winter?

Hardy to −7 °C: protect in harsh winters.

• Not fully hardy: it tolerates light frost down to about −7 °C, but not if the roots freeze in a pot.
• Bring it indoors in October, before the first frost, to a bright, cool (5–10 °C), frost-free spot: an unheated conservatory or a light cellar. Water sparingly: the root ball must just not dry out. No feeding.
• In a mild area it can stay against a south wall, with a thick layer of mulch and fleece in frost; be aware that it may die in a hard winter.

Diseases and pests

• Yellow leaves: Caused by hard water or limy soil (iron deficiency). Water with rainwater and use ericaceous compost.
• Scale insects and red spider mite: Mainly during indoor overwintering: sticky leaves, brown scales or fine webbing. Wipe scale off with a damp cloth, rinse the foliage and ventilate regularly.
• Brown, falling leaves: Caused by drying out or, conversely, wet feet in the pot. Keep the root ball slightly moist and make sure water can drain away.
• No flowers: Too little light or pruned too hard. Give it full sun and prune only lightly after flowering.

Through the year

• March: Indoors in a bright, cool spot. Little water.
• April: Repot if needed. Water a little more.
• May: After mid-May, put outside or plant out. Feed monthly.
• June: Flowering begins. Water regularly.
• July: Full flower. Water in dry weather.
• August: Flowering ends. Light pruning. Take cuttings.
• September: Light pruning. Take cuttings.
• October: Bring indoors before the first frost.
• November: Overwinter cool and bright, little water.
• December: Resting indoors, almost no water.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• It used to be called Callistemon citrinus; that genus has been merged into Melaleuca since the 2000s.
• The red ‘brush’ is made of long stamens, not petals.
• The woody capsules often stay clustered around the branch for years.