Lavender-cotton

Lavender-cotton: how do you recognise it?

Habit

Compact, rounded shrublet 0.3–0.5 m tall and about 0.6 m across, with a woody base.

Leaf

Alternate, 2–4 cm, narrow and set all round with short, thick teeth, silvery-grey and felted; smells aromatic when touched.

Twigs

Woody base with grey, felted twigs.

Flower

Rounded, bright yellow flower heads (1–2 cm) without ray florets, single on long stalks, June–August.

Fruit

Small nutlets without a pappus.

Difference from English lavender

Lavender has narrow, untoothed leaves and purple flower spikes.

Difference from curry plant

Curry plant (Helichrysum italicum) has silvery-grey, needle-like leaves that smell of curry, and yellow flowers in clusters.

Flowering: July–August · Pruning: April and August–September

Looks like it, but isn’t

• English lavender Lavandula angustifolia: narrow, untoothed leaves and purple flower spikes. Difference from English lavender
• Curry plant (Helichrysum italicum): silvery-grey, needle-like leaves that smell of curry, and yellow flowers in clusters.

Why grow it?

• Silvery-grey foliage that stays all year and makes other colours in the border glow.
• A low hedge or edging you can clip neatly, even on dry, poor soil.
• Yellow button flowers in summer for bees and hoverflies.
• Takes hard pruning better than lavender.

Lavender-cotton: where does it grow best?

• Full sun; in shade it grows floppy and falls open.
• Dry, poor, well-drained soil, chalky or not; no wet roots in winter.
• On heavy clay: plant on a raised bed, a low wall or a slope, or work coarse sand and gravel into the soil.
• Lovely as a low edging along a path, in a gravel garden, rock garden or large pot.

Light

Full sun

Legal basis

Any garden soil

Moisture

Dry

Size

0.5 m tall, 0.6 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• English lavender: Purple flower spikes beside silver-grey foliage and yellow buttons: a classic pairing for a dry, sunny edge.
• Common sage: A greyish-green kitchen herb for the same dry spot; together a fragrant herb garden.
• Rosemary: Dark green, needle-like leaves as a contrast to the silver-grey of lavender-cotton.

Good and bad companions

Best kept away from

• Do not plant under the dense crown of these trees: norway spruce, european silver fir, nordmann fir, douglas fir, yew, horse chestnut, norway maple, sycamore

Lavender-cotton: when and how to plant it?

1. Plant in April–May, so it is well rooted before the wet winter.
2. For a low hedge, plant every 30–40 cm; as a single plant, allow about 60 cm.
3. Don’t plant it deeper than it was in the pot, and mulch with gravel if you like, not with compost or bark.
4. In a pot: compost mixed with grit or sand, and a drainage hole.

Care

Watering

Only for the first few weeks after planting and in a pot; after that it copes on its own.

Feeding

Not needed: on rich soil it grows floppy and falls open.

Flower buds

If you only want the silver foliage, cut off the flower buds before they open: the plant then stays more compact.

Renewal

An old plant that falls open and goes bare can be cut back hard in April or replaced with a cutting.

Tip: For a crisp, silvery edging, cut off the flower buds as soon as you see them. If you let it flower, bees and hoverflies will feast on it: choose what you would rather see.

Lavender-cotton: when to prune it?

Pruning months: April and August–September.

When: After flowering (August–September) and in April.

How:

• After flowering, cut off the spent flower stalks and lightly reshape the plant.
• In April you can cut it back hard to 10–15 cm: it regrows from old wood better than lavender and stays compact that way.
• Clip a low hedge every year, so it stays dense right to the base.

Caution: Don’t prune in late autumn or winter: wait until April for the hard prune, when the worst frosts are over.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In July–August, take cuttings of 5–10 cm from non-flowering shoots, ideally with a heel, and root them in a sandy mix.

Layering

In spring, peg a low branch into the soil and cover it; once it has rooted, cut it free.

Lavender-cotton: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Hardy in our climate as long as the soil doesn’t stay wet: wet winters are more dangerous than frost.
• Let the plant go into winter with its leaves and wait until April for the hard prune.
• In winter, stand pots in a sheltered, dry spot, raised on pot feet.

Diseases and pests

• Falling open: The plant splits open in the middle, especially after flowering or heavy rain. Trim after flowering and cut back hard in April.
• Root rot: The plant turns brown and dies after a wet winter. Replant in a drier, better-drained spot.
• Bare and woody: A plant left unpruned for years goes bare at the base. Cut it back to 10–15 cm in April or replace it.

Through the year

• April: Hard prune to 10–15 cm; planting.
• May: Planting and potting up.
• June: Flowering begins: bees and hoverflies.
• July: Full flower; taking cuttings.
• August: Pruning after flowering: remove spent flower stalks; cuttings.
• September: Last pruning after flowering; lightly clip a low hedge into shape.
• November: Move pots to a dry, sheltered spot.

What can you use it for?

Garden and landscape

Low, silvery-grey hedge or edging in a dry, sunny garden; a classic in herb and knot gardens.

For wildlife

The yellow buttons attract bees and hoverflies.

Also used for

Dried sprigs among clothes keep moths away.

Did you know?

• Chamaecyparissus means ‘dwarf cypress’, but it is a member of the daisy family: each yellow button is a flower head full of tiny disc florets, like the centre of a daisy.
• Dried sprigs among clothes keep moths away.
• In the knot gardens of the 16th and 17th centuries, lavender-cotton was clipped into low hedges in elaborate, interlacing patterns.