Jerusalem sage

Jerusalem sage: how do you recognise it?

Habit

Broad, rounded shrub about 1 m tall and 1.2 m wide, woody at the base, with square, woolly stems.

Leaves

Oval to lance-shaped, 5–10 cm long, wrinkled and densely felted, grey-green above and almost white beneath.

Flowers

Bright yellow hooded flowers of 2.5–3 cm in dense whorls around the upper parts of the stems, in June and July.

Seed heads

After flowering, brown, rounded whorls remain and stay attractive into winter.

Roots

Deep and woody: once established it draws water from deeper soil.

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

Why grow it?

• Evergreen, grey felted leaves that look soft and silvery all year round.
• Striking whorls of bright yellow flowers in June and July.
• A real bee and bumblebee plant while in flower.
• Very drought-tolerant: after the first year it never needs watering.
• The dry seed whorls add structure to the winter garden.
• Low-maintenance: one prune in April is enough.

Jerusalem sage: where does it grow best?

• Full sun, as warm as possible: the more sun, the more silvery the leaves and the better the flowering.
• Poor, free-draining soil: sand, loam or clay with grit added, acid to chalky.
• Dry: it tolerates long droughts but not waterlogging, especially in winter.
• Ideal in a gravel garden, on a sunny bank, against a warm wall or in a Mediterranean border.
• Allow 1–1.2 m per plant.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry

Size

1 m tall, 1.2 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Lavender: Purple beside the yellow, for the same dry, sunny spot.
• Rock rose: Also Mediterranean, evergreen and drought-tolerant.
• Catmint: Blue flowers and a soft shape at the base.
• Russian sage: Silver-grey leaves and blue flowers in late summer, after the Jerusalem sage has finished.
• Feather grass: Airy plumes between the sturdier shrubs.

Jerusalem sage: when and how to plant it?

Plant in April–May.

1. Plant in April–May, once the soil has warmed up, so it roots in well before winter.
2. Dig a hole twice as wide as the root ball. On heavy soil, mix in coarse sand or grit; compost is not needed.
3. Set the plant at the same depth as in the pot and firm the soil.
4. Plant 1–1.2 m apart.
5. Water when planting, and in dry spells for the first few weeks.
6. Mulch with gravel rather than compost: it keeps the base dry.

Care

Water

Only in long dry spells during the first year. After that, no watering is needed.

Feeding

Do not feed: on rich soil it grows floppy and becomes less hardy.

Mulching

Use gravel or grit, not compost or bark: it keeps the base dry.

Spent flowers

Leave the seed whorls for winter, or cut them off after flowering for a tidier look.

Renewal

After a number of years it often becomes woody and open. Replace it then with a young plant grown from a cutting.

Tip: Give it a dry, sunny spot without compost or fertiliser: the poorer the soil, the more compact and hardy it stays. Cut off the old flower stems in April.

Jerusalem sage: when to prune it?

Pruning months: April and August.

When: In April, cut off the old flower stems and frosted tips. After flowering, in August, you can trim it lightly to keep it compact.

How:

• In April, cut the old flower stems back to just above a pair of leaves or new shoots.
• At the same time, shorten the whole shrub by about a third so it stays compact and full.
• Do not cut into old, bare wood: it is slow to regrow from there.
• If you do not want seed heads in winter, cut off the faded stems in August.

Caution: Do not prune in late autumn: fresh cuts and young shoots are then vulnerable to frost.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In July–August: cuttings of 8–10 cm from non-flowering shoots, lower leaves removed, in a sandy cutting mix. Keep them barely moist, never wet, in a bright spot out of direct sun.

Layering

In spring, peg a low stem against the soil and cover it with a little sandy soil; sever and transplant it after a year.

Jerusalem sage: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Hardy to about −15 °C, provided the soil is dry. In wet soil it is much more vulnerable.
• After a hard winter the tips may be frosted; cut them off in April and it will regrow from below.
• Leave the seed whorls: they decorate the winter garden, especially with frost on them.
• In a pot: stand it against a warm wall, out of the rain, and make sure water drains away freely.

Diseases and pests

• Root rot: The plant suddenly dies in winter or spring. Cause: wet, heavy soil. Plant on a raised bed or mix plenty of grit into the soil.
• Bare, sprawling shrub: Over the years it falls open and becomes bare at the base. Prune every April, or replace it with a young plant.
• Frost damage: Brown, withered tips after a hard winter. Wait until April and cut back to where new shoots appear.
• Cuckoo spit: Blobs of white froth on the stems in May, each with a small froghopper nymph inside. Harmless; hose them off if they bother you.

Through the year

• January: Dormant. Grey leaves and dry seed whorls decorate the winter garden.
• April: Cut off old flower stems and trim lightly into shape. Plant.
• May: Plant. The first flower buds appear.
• June: Flowering: yellow whorls full of bumblebees.
• July: Flowering. Take cuttings.
• August: After flowering, trim lightly if you wish. Take cuttings.
• September: Leave the seed whorls for winter.
• November: No compost or fertiliser: it prefers to go into winter dry.
• December: Frosted seed whorls in the garden.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Despite its name, it is not a true sage, although both belong to the mint family.
• The felt is made up of tiny star-shaped hairs that protect the leaf from drying out in fierce sun.
• The flowers sit in whorls around square stems, typical of the mint family, as in mint and lavender.