Mossy saxifrage

Mossy saxifrage: how do you recognise it?

Habit

Dense, low cushion about 15 cm tall in flower and up to 40 cm wide.

Leaves

Small rosettes of finely divided, fresh green leaves; evergreen.

Flower

Cup-shaped flowers about 1 cm across on slender stems above the cushion.

Colour

White, pink, red or crimson, sometimes with a paler centre.

Roots

Shallow and fine; the shoots root where they touch the soil.

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

Why grow it?

• Evergreen cushions that cover the ground all year round.
• A carpet of little flowers in April and May, together with the spring bulbs.
• Ideal for spots in half shade: at the foot of a wall, between stones or as an edging along a path.
• Suppresses weeds once the cushions have closed up.
• Low-maintenance: just cut off the flower stems after flowering.

Mossy saxifrage: where does it grow best?

• Half shade or light shade; in full sun the cushions turn brown in summer.
• Free-draining sandy or loamy soil, acid, neutral or chalky.
• Normally moist: do not let it dry out, but avoid wet feet in winter.
• Ideal between stones, at the foot of a wall, in a rock garden or as an edging along a path.
• Plant 25–30 cm apart for a closed carpet.

Light

Partial shade and shade

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Normal

Size

0.15 m tall, 0.4 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Grape hyacinth: Blue flower spikes that rise above the cushions.
• Siberian bugloss: Sky-blue flowers at the same time, for half shade.
• Coral bells: Coloured leaves as a backdrop for the low cushions.
• Auricula: Another rock garden plant, with scented flowers around the same time.
• Maidenhair spleenwort: A small fern for walls and stones, just like the mossy saxifrage.

Mossy saxifrage: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October.
2. Loosen the soil and mix in a little compost and, on heavier soil, coarse sand.
3. Set the plant at the same depth as it was in the pot; the cushion must not be buried.
4. Leave 25–30 cm between plants.
5. Firm the soil and water in straight away.
6. If you like, scatter a thin layer of fine grit between the plants: it keeps the underside of the cushions dry.

Care

Water

Water during long dry spells, especially in the first summer and in a warm spot.

Feeding

Little needed: a thin layer of compost between the cushions in spring.

Spent flowers

Clip or shear off the flower stems after flowering; this keeps the cushion compact and tidy.

Bare patches

Scatter some sandy soil into brown or bare patches; they often grow over again.

Rejuvenating

Divide every three to four years, as old cushions go bare in the centre.

Tip: Give it a spot with morning sun and afternoon shade, for example on the east side of a wall or rock: there it flowers freely without scorching.

Mossy saxifrage: when to prune it?

Pruning months: June.

When: After flowering, in June. Otherwise it is not pruned.

How:

• Clip or shear off the faded flower stems just above the cushion.
• Cut out brown, dead rosettes to keep the cushion healthy.
• In autumn and spring, remove fallen leaves from the cushions, or they will rot underneath.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

After flowering or in September, split a cushion into rooted pieces and replant them straight away. Water well.

Rosette cuttings

In May–June, detach single rosettes and insert them in a pot of sandy cutting compost, in shade and slightly moist. They root within a few weeks.

Mossy saxifrage: how does it get through the winter?

Hardy to −25 °C.

• Hardy to about −25 °C: no protection is needed in Belgium.
• Evergreen: the cushions stay green in winter.
• Wet feet and a layer of rotting leaves are more dangerous than frost: remove fallen leaves and ensure good drainage.
• In a pot or trough: stand it against a wall and make sure there is a drainage hole.

Diseases and pests

• Brown cushions: Caused by strong sun or drought in summer. Water, move the plant to half shade and fill bare patches with sandy soil.
• Rot: Brown, slimy patches after a wet winter or under a layer of leaves. Remove the leaves, cut out rotten parts and improve drainage.
• Vine weevil: The grubs eat the roots, so patches of cushion die. Use nematodes against the grubs.
• Birds: Blackbirds and sparrows sometimes pull pieces out of the cushion. Press loosened pieces back down and water.

Through the year

• March: Plant. Clear fallen leaves from the cushions. Give a thin layer of compost.
• April: Flowering starts.
• May: Full flower.
• June: Cut off faded flower stems. Take rosette cuttings.
• July: Water in dry, hot weather.
• August: Water in dry spells. Fill bare patches with sandy soil.
• September: Plant and divide.
• October: Plant. Clear fallen leaves from the cushions.

Did you know?

• Saxifraga means ‘stone-breaker’: many species grow in rock crevices, as if they were splitting the stone.
• Despite its name, mossy saxifrage is not a moss but a flowering plant; only its fine leaves bring moss to mind.
• Georg Arends, after whom these hybrids are named, also raised many well-known astilbe cultivars, Astilbe × arendsii.