Sage-leaved rockrose

Sage-leaved rockrose: how do you recognise it?

Habit

A low, spreading, somewhat sprawling shrub about 60 cm tall and 1 m wide.

Leaves

Small, oval and wrinkled, grey-green and softly hairy, like sage leaves.

Flowers

White, saucer-shaped flowers about 4 cm across with five slightly crumpled petals and a yellow centre, in May–June; each flower lasts one day.

Fruit

Small, round seed capsules that stay on the shrub after flowering.

Roots

Deep and branching; once established it does not like being moved.

Flowering: May–June · Plants: April–May · Pruning: July

Why grow it?

• White flowers with a yellow centre, new ones every day, in May–June.
• One of the hardier rockroses.
• Evergreen and spreading: attractive ground cover for a dry, sunny bank.
• Very drought-tolerant: once established in open ground it needs no extra water.
• Bees love its abundant pollen.
• Little work: no fertiliser and rarely any pruning.

Sage-leaved rockrose: where does it grow best?

• Full sun: the warmer and sunnier, the better.
• Sandy or loamy, well-drained soil, acid to chalky; poor soil is fine.
• Dry: soil that stays wet in winter is fatal.
• Ideal on a bank, in a rock or gravel garden, or tumbling over a low wall.
• Allow about 1 m of space per plant.

Light

Sun

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Dry

Size

0.6 m tall, 1 m wide

Hardiness

Half hardy (to -12 °C): protect it in harsh winters

Goes well with

• Lavender: Likes the same dry, sunny spot and flowers after the rockrose.
• Rosemary: Aromatic grey-green foliage for a Mediterranean corner.
• Thyme: A low, scented ground cover to plant in between.
• Ceanothus: Blue spring flowers against a wall behind the white rockrose.
• Feather grass: Light, swaying plumes in a gravel garden.

Sage-leaved rockrose: when and how to plant it?

Plant in April–May.

1. Plant in April–May, so that it is well rooted before winter.
2. Dig a hole a little wider than the pot; if the soil is rather heavy, mix in coarse sand or gravel.
3. Set the plant at the same depth as it was in its pot, or slightly higher, so that the base stays dry.
4. Leave about 1 m between plants.
5. Water in when planting and then only in dry spells during the first few weeks.
6. Mulch with gravel rather than compost: this keeps the base dry and warm.

Care

Watering

Only in dry spells during the first few weeks after planting; after that not at all, even in hot summers. Water a plant in a pot now and then.

Feeding

Do not feed: fertiliser gives soft growth, fewer flowers and a shorter life.

Mulching

A layer of gravel around the base keeps it dry in winter.

In a pot

Use a pot with a drainage hole and a mix of compost and coarse sand or gravel; do not leave water standing in the saucer.

Back-up

Rockroses are not long-lived: take a few cuttings every few years as a back-up.

Tip: Plant it at the top of a bank or on a low wall where it can tumble over: the base stays dry in winter and its spreading habit is shown off best. Never feed it.

Sage-leaved rockrose: when to prune it?

Pruning months: July.

When: Rockrose needs little pruning. After flowering, in July, trim lightly at most to keep it compact.

How:

• Shorten the flowered shoots by a third at most, within the green, leafy part.
• Never cut into old, bare wood: it will not reshoot from it.
• Dead or frosted twigs can be removed at any time, best in spring when you can see what is still alive.

Caution: It does not tolerate hard pruning: a bare, overgrown shrub is better replaced with a young plant.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In July–August, take 8–10 cm cuttings from non-flowering shoots, remove the lower leaves and root them in gritty compost. They root easily; overwinter them frost-free and on the dry side.

Seed

Sow in spring in gritty compost; the hard seed germinates better after a brief soak in hot water.

Sage-leaved rockrose: how does it get through the winter?

Hardy to −12 °C: protect in harsh winters.

• Hardy to about −12 °C: in a dry, sunny, sheltered spot it survives most Belgian winters.
• Wet soil combined with frost is its greatest enemy: make sure drainage is excellent.
• Cover it with fleece in severe frost and take a few cuttings in summer as a back-up.
• In a pot: keep it dry and sheltered in winter, for example under a canopy or in a cool, light, frost-free room.

Diseases and pests

• Root rot: The plant suddenly withers, often after a wet winter. Prevent it with a dry, well-drained spot; an affected plant can rarely be saved.
• Frost damage: Brown leaves and dead twigs after a harsh winter. Wait until new growth starts, then cut out the dead wood.
• Soft, open growth: Caused by too much shade, water or fertiliser. Move it to full sun and stop feeding.
• Bare, woody shrub: Normal after a number of years. Replace it with a young plant raised from a cutting.

Through the year

• January: In severe frost, cover with fleece.
• March: Remove the fleece once the hardest frosts are over.
• April: Plant. Apply a gravel mulch.
• May: Flowering begins. Plant.
• June: Full flower: new blooms every day.
• July: After flowering, trim lightly. Take semi-ripe cuttings.
• August: Take cuttings. No watering needed in open ground.
• October: Move cuttings and pots to a dry, frost-free place.
• November: Make sure the base stays dry. Have fleece ready.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Each flower lasts only one day and then drops its petals, but the plant opens new ones every morning for weeks.
• In the wild, rockroses often germinate in great numbers after a fire: the heat makes the hard seed coat permeable.
• Related species, such as Cistus ladanifer, produce a sticky, fragrant resin called labdanum, which is used in perfumery.