Herbs

Rosemary

SalviaLamiaceae
AT A GLANCE
Full sun Water: little H4down to −10 °C 1–1.5 m tall · 1–1.5 m wide In a pot: yes
Flowering · UK
Flowering · Northern Italy
Flowering · Central Italy
Flowering · Southern Italy and islands

The genus covers three quite different plants: the hardy border salvias that come back every year, the tender ones like 'Amistad' and the microphylla hybrids that flower until Christmas in a mild autumn but need a dry winter to survive, and culinary sage and rosemary, which are Mediterranean sub-shrubs.

What unites them is drainage. Salvias survive cold far better than they survive winter wet, so a gritty soil or a raised spot does more for them than any fleece.

Care

Light

Sheltered — essential for both flavour and hardiness.

Water

A classic Mediterranean herb that dislikes wet feet once established.

Soil

Free-draining soil of poor-to-moderate fertility; excellent on chalky/alkaline ground; add grit to heavy clay or grow in a pot.

Pruning

Trim lightly after flowering to keep a compact shape; avoid cutting back hard into old bare wood, which is slow to reshoot or may not recover at all.

Feeding

Doesn't want feeding in the ground — lean soil gives the concentrated, aromatic growth you actually want in the kitchen. A plant in a pot is the one exception: a weak balanced feed a couple of times over the growing season keeps it from exhausting its compost.

Propagation

Semi-ripe cuttings in summer: a 10cm side-shoot pulled off with a heel, lower leaves stripped, in gritty compost. Cheap and quick, and worth doing before a hard winter on an older, woody plant.

Month by month

Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.

  1. MayEnjoy the flowers, attractive to early pollinators.
  2. JuneTrim lightly after flowering to keep a compact, bushy shape. how ›
  3. SeptemberHarvest sprigs for cooking and drying — best flavour just before flowering.

Months based on climate: UK. Your choice stays on this device.

  1. MayEnjoy the flowers, attractive to early pollinators.
  2. JuneTrim lightly after flowering to keep a compact, bushy shape. how ›
  3. SeptemberHarvest sprigs for cooking and drying — best flavour just before flowering.

Months based on climate: Northern Italy. Your choice stays on this device.

  1. AprilEnjoy the flowers, attractive to early pollinators.
  2. MayTrim lightly after flowering to keep a compact, bushy shape. how ›
  3. SeptemberHarvest sprigs for cooking and drying — best flavour just before flowering.

Months based on climate: Central Italy. Your choice stays on this device.

  1. AprilEnjoy the flowers, attractive to early pollinators.
  2. MayTrim lightly after flowering to keep a compact, bushy shape. how ›
  3. OctoberHarvest sprigs for cooking and drying — best flavour just before flowering.

Months based on climate: Southern Italy and islands. Your choice stays on this device.

Common problems

Root rot

How to spot it. In heavy, waterlogged soil.

What to do. Improve drainage or grow in a pot.

Rosemary beetle

How to spot it. Metallic green-and-purple striped beetle, can strip foliage.

What to do. Hand-pick if seen.

Legginess/bare stems

How to spot it. From infrequent light trimming or deep shade.

What to do. Trim lightly and regularly from the start; move to a sunnier spot.

Popular varieties

Salvia ‘Miss Jessopp's Upright’AGM1.2–1.5 m × 60–90 cm · March–MayMarch–MayFebruary–AprilFebruary–April
Salvia ‘Prostratus’30–45 cm × 60–90 cm · March–MayMarch–MayFebruary–AprilFebruary–April
Salvia ‘Tuscan Blue’1.5–2 m × 1 m · March–MayMarch–MayFebruary–AprilFebruary–April

Questions

Rosemary: is it hardy?

H4: Hardy through an average UK winter. It survives down to −10 °C.

Can it grow in a pot?

A good choice for a pot, especially on heavy clay soil where drainage is a concern.

Rosemary: when do you prune it?

Trim lightly after flowering to keep a compact shape; avoid cutting back hard into old bare wood, which is slow to reshoot or may not recover at all. In the calendar for UK, pruning falls in June.

Rosemary: when does it flower?

In the climate of UK it flowers in April–May.

When do you feed it?

Doesn't want feeding in the ground — lean soil gives the concentrated, aromatic growth you actually want in the kitchen. A plant in a pot is the one exception: a weak balanced feed a couple of times over the growing season keeps it from exhausting its compost.