Russian sage

Russian sage: how do you recognise it?

Habit

Upright, airy subshrub 1–1.2 m tall and 60–90 cm wide; woody at the base.

Leaves

Grey-green, 3–6 cm, deeply cut to toothed, opposite; smell of sage.

Flower

Small, lipped flowers in long, branched plumes, from July to October.

Colour

Lavender-blue to violet, with grey-white, felted calyces and stems.

Stems

Square and silvery-white; they become woody at the base and stay standing in winter.

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

Why grow it?

• Flowers for a very long time, from July into October, in a haze of lavender-blue plumes.
• Very drought-tolerant: one of the best plants for a sunny gravel garden.
• Bees and butterflies flock to it all through late summer.
• The leaves are aromatic, and the silver stems stay attractive in winter.
• Low-maintenance: one prune a year, no feeding and hardly any watering.

Russian sage: where does it grow best?

• Full sun: in shade it goes floppy and flowers poorly.
• Poor, free-draining sandy or loamy soil, neutral to chalky.
• Dry: in wet, rich soil it falls over and the roots may rot.
• Plant 60–80 cm apart; in a group or as a low, informal hedge at 50–60 cm.

Light

Sun

Soil type

Sand or loam

Acidity

Neutral or chalky

Moisture

Dry

Size

1.2 m tall, 0.9 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Sedum: Flat, pink flower heads beside the blue plumes, in the same dry sun.
• Fountain grass: Fluffy plumes that sway with the blue haze in late summer.
• Coneflower: Pink daisies that flower at the same time and also attract bees.
• Globe thistle: Blue globes with blue plumes, both for dry soil.

Russian sage: when and how to plant it?

Plant in April–May.

1. Plant in April–May, once the soil has warmed up.
2. Dig a hole twice as wide as the root ball; in heavy soil mix in coarse sand or gravel.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. Leave 60–80 cm between plants.
5. Water in well and in dry weather for the first few weeks; spread gravel around the base if you like.

Care

Watering

Only in the first season during dry spells. After that hardly ever; in a pot now and then.

Feeding

Not needed. Fertiliser and compost give soft, weak stems that flop.

Mulching

Gravel or nothing; organic mulch keeps the soil too damp.

Support

Not needed in poor soil. If it flops, a ring helps, but the soil is probably too rich.

Deadheading

Leave the flowers: the plumes stay grey and silver into winter.

Tip: Do not cut back in autumn but in April, to 30 cm: the silver stems look good in winter and the plant then regrows strongly.

Russian sage: when to prune it?

Pruning months: April.

When: In April, when the new buds swell at the base of the stems. Not in autumn: the stems look good in winter and protect the plant.

How:

• Cut all stems back to about 30 cm above the ground, just above a few buds.
• Remove dead, thin and damaged stems right at the base.
• Do not prune too lightly: stems left long go bare and fall over more easily.

Caution: Do not cut down to the ground into old wood without buds: it is slow to regrow from there.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Softwood cuttings

In May–June, take 8–10 cm cuttings from young shoots, strip the lower leaves and insert them in sandy cutting compost under plastic. They root within a few weeks.

Suckers

In light soil it sometimes produces suckers. In April, dig up a piece with roots and replant it elsewhere.

Russian sage: how does it get through the winter?

Hardy to −25 °C.

• Hardy to about −25 °C: no protection needed in Belgium, as long as the soil does not stay wet.
• Leave the silver stems until April: they make a fine winter silhouette, especially with frost on them.
• In a pot: stand it against a wall, out of the rain, and do not water in winter.

Diseases and pests

• Flopping: The stems splay open or lie flat. The cause is soil that is too rich or wet, too much shade or too light a prune. Do not feed and cut back hard in April.
• Root rot: The plant fails to reshoot in spring. The cause is wet, heavy soil in winter. Replant in a dry, sunny spot.
• Few flowers: Too much shade or too much fertiliser. Move it to full sun in April.
• Suckers: In sandy soil, shoots sometimes appear beside the plant. Remove them or use them for propagation.

Through the year

• January: Rest. The silver stems decorate the garden.
• April: Cut back to 30 cm. Planting. Lift suckers.
• May: Planting. Take cuttings.
• June: Take cuttings. Water young plants in dry spells.
• July: Flowering begins.
• August: Full flower. Bees and butterflies on the plumes.
• September: Flowering. No water or feeding needed.
• October: Last flowers. Leave the stems standing.
• December: Rest. Keep potted plants dry.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The old genus name Perovskia honours the Russian general Vasily Perovsky, hence the name Russian sage.
• Following DNA research, the genus Perovskia was merged into Salvia in 2017, so Perovskia atriplicifolia is now called Salvia yangii.
• The silvery-white colour of the stems comes from a layer of fine hairs.