Rosemary

Rosemary: how do you recognise it?

Habit

Evergreen shrublet of 0.5–1.5 m, upright or, in creeping varieties, prostrate.

Leaf

Opposite, 2–4 cm, narrow, needle-like and leathery; dark green above, white-felted below, with a rolled-under edge.

Stems

Greyish-brown, woody and often twisted stems.

Flower

Pale blue, two-lipped flowers in the leaf axils, March–May, and often again in autumn.

Fruit

Small nutlets.

Difference from English lavender

Lavender has greyer, softer leaves and flower spikes on long stalks in summer.

Flowering: March–May · Harvest and fruit: January–December · Pruning: May–June

Identify by feature: Long, narrow leaves · Purple or blue flowers

Looks like it, but isn’t

• English lavender Lavandula angustifolia: greyer, softer leaves and flower spikes on long stalks in summer. Difference from English lavender

Why grow it?

• A fresh herb all year round, for potatoes, lamb, bread and oil.
• Flowers early in spring: important for bees and bumblebees.
• Evergreen and fragrant: lovely as edging or a low hedge.
• Tolerates drought well once established.

Rosemary: where does it grow best?

• Full sun, ideally warm and sheltered, for example in front of a south-facing wall.
• Dry, well-drained, not too rich soil; heavy clay that stays wet in winter is its worst enemy.
• On heavy soil: plant it in a raised bed, mix in gravel and coarse sand, or grow it in a pot.
• Allow for about 1 m tall and wide.

Light

Full sun

Legal basis

Any garden soil

Moisture

Dry

Size

1 m tall, 1 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• English lavender: Needs the same full sun and dry soil; together a fragrant Mediterranean corner.
• Garden thyme: A low, fragrant herb for the edge, with the same needs.
• Common sage: Another evergreen kitchen herb for the same sunny, dry spot.
• Lavender-cotton: Grey leaves and yellow button flowers beside the dark green of the rosemary.

Good and bad companions

Best kept away from

• Do not plant under the dense crown of these trees: norway spruce, european silver fir, nordmann fir, douglas fir, yew, horse chestnut, norway maple, sycamore

Rosemary: when and how to plant it?

1. Plant in spring (April–May), so that it is well rooted before winter.
2. Ensure good drainage: mix coarse sand or gravel into the planting soil.
3. Plant at the same depth as in the pot, no deeper.
4. In a pot: choose a pot with a drainage hole and herb compost mixed with some coarse sand.

Care

Watering

Only in dry spells during the first year, and for plants in pots; rarely after that. Too much water is worse than too little.

Feeding

Not needed: on rich soil it grows soft and less fragrant.

Harvest

Cut sprigs all year round; a little more sparingly in winter, when it hardly grows.

In a pot

In winter, stand the pot on pot feet so the water can drain away, against a sheltered wall.

Tip: Plant rosemary close to the kitchen door, in the sunniest and driest spot in the garden: that is where you will pick it most, and where it will come through the winter best.

Rosemary: when to prune it?

Pruning months: May–June.

When: After flowering, in May–June.

How:

• Cut the year’s growth back by a third, but never into the bare, old wood: it will not regrow from there.
• Trim a little every year: the shrub stays compact and does not go bare at the base.
• After a hard winter, cut out the dead, frosted wood as soon as you can see where it is regrowing.

Caution: Fairly frost-tolerant, but dislikes wet feet in winter.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In July–August, take 10 cm cuttings from non-flowering shoots, strip the lower leaves and root them in gritty compost.

Layering

Peg a low branch down to the ground and cover it; after a few months it will have roots.

Rosemary: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• In well-drained soil and a sheltered spot it tolerates about −10 °C; varieties such as ‘Arp’ take a little more. Wet soil and cold, dry east winds often do more damage than the frost itself.
• In severe frost, cover the plant with fleece, and move potted plants against a sheltered wall or into a cool, light, frost-free place.

Diseases and pests

• Wet feet: Brown, dried-looking leaves and dying branches, caused by root rot in wet soil, often in winter. Plant in a well-drained spot.
• Rosemary beetle: Small, metallic beetles striped green and purple, and grey larvae, feed on the leaves, on lavender, sage and thyme too. Shake them off over a newspaper and dispose of them.
• Woody, bare plant: An old plant that has never been trimmed goes bare at the base and falls open. Replace it with a new cutting: it will not regrow from bare wood.
• Frost damage: Brown tips after a hard winter. Wait until May to see what is still alive, then cut out the dead wood.

Through the year

• March: Flowering begins: food for the first bees.
• April: Planting; if there is frost damage, wait a little longer.
• May: Prune after flowering: cut the year’s growth back by a third, remove dead wood.
• June: Finish pruning; harvest.
• July: Take cuttings.
• August: Take cuttings; harvest sprigs for drying.
• October: Often a second, smaller flush of flowers.
• November: Move potted plants to shelter; have fleece ready for severe frost.

What can you use it for?

Food and drink

Herb for potatoes, lamb, bread and oil; fresh all year round.

For wildlife

Flowers early: important for bees and bumblebees in spring.

Garden and landscape

Fragrant edging or low hedge in a sunny, dry spot.

Edible and useful

Leaves (January–December)

Cut young sprigs all year round; in summer, just before or during flowering, the aroma is strongest. For potatoes, lamb, chicken, bread, focaccia, marinades and herb salt. Rosemary is also traditionally used in a hair rinse or a herbal bath.

Flowers (March–May)

The pale blue flowers (March–May) are edible and taste mildly of rosemary: scatter them over a salad or a tart, or freeze them in ice cubes.

Storing

As the plant is evergreen, it is usually simply picked fresh. You can also dry sprigs in bunches in an airy, dark place, then strip off the needles and keep them in a closed jar. Or chop the needles and freeze them in oil in an ice-cube tray.

Caution: Do not confuse rosemary with the highly poisonous yew: yew has flat, scentless needles. Rosemary smells strongly aromatic as soon as you crush it. Do not leave fresh rosemary or garlic in oil at room temperature for long: this can lead to botulism. Keep home-made herb oil in the fridge and use it within a week. Use rosemary in normal culinary amounts; the essential oil is not for swallowing.

Eating and using is at your own risk: see the terms of use.

Recipes

• Rosemary and lemon salt (Dried · 1 small jar of about 175 g · 15 min + 1–2 days drying)
• Rosemary hair rinse (Skin and body care · ± 500 ml (2 to 3 rinses) · 10 min + 30 min steeping)
• Rosemary focaccia (Dish · makes 1 tray (12 pieces) · 30 min + 1½ hours rising + 25 min baking)
• Rosemary and rosemary flower vinegar (Vinegar · makes ± 500 ml · 10 min + 2 weeks infusing)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Bumblebees

Nectar and pollen for bumblebees, also from deep flowers and early in spring.

Did you know?

• Botanists have recently moved rosemary into the sages: Salvia rosmarinus instead of Rosmarinus officinalis.
• The old name rosmarinus means ‘dew of the sea’: in the wild it often grows close to the Mediterranean.
• The old name rosmarinus means ‘dew of the sea’: around the Mediterranean, rosemary likes to grow close to the coast.
• Rosemary has stood for remembrance for centuries. In Shakespeare’s Hamlet, Ophelia says: ‘There’s rosemary, that’s for remembrance.’