How to Care for Rosemary in a Mediterranean Climate

Rosemary (Salvia rosmarinus, still sold under its old name Rosmarinus officinalis) is one of the easiest herbs we grow on our Quinta in Central Portugal. It grows here alongside our lavender, it asks for very little, and most of the trouble people have with it comes from giving it too much: too much water, too much feed, too much pruning in the wrong place. If you garden in USDA Zones 8 to 10, here's how I look after it.

Our upright rosemary at the path fork, flowering with almost no extra water once it was established. It sits in full sun on free-draining ground and has stayed compact with light pruning.

Quick Answer: How to Care for Rosemary

Give rosemary the sunniest, driest spot you have, in soil that drains fast. Water young plants regularly through their first summer, then cut back hard on watering once they're rooted. Skip heavy feeding, mulch lightly with gravel or a thin organic layer kept off the stem, and prune lightly after flowering without cutting into old bare wood.

The one warning that matters most: rosemary handles drought far better than it handles wet feet. Soggy winter soil kills more rosemary than any summer heatwave.

Best Light and Placement for Rosemary

Rosemary wants full sun, ideally 6 to 8 hours or more a day, and it loves reflected heat from stone walls, rocky slopes and paths. It tolerates light shade, but it gets leggier and flowers less there.

Light-purple blooms on the upright rosemary in full sun. Flowering is heaviest where the plant gets six hours or more, and I prune lightly once the flowers fade.

On our Quinta we've planted upright rosemary in several spots, mostly from free cuttings collected locally. Ours do best in full sun. One I planted on the shady side of a little fence line by our veggie terrace seems to have died, though something may also have eaten its roots. Another one planted out in the greenhouse is growing well.

Avoid frost pockets and low ground where cold air and damp settle. A slope or a raised bed near a south-facing wall is close to perfect. Freshly rooted cuttings are the exception to the full sun rule: in a hot Central Portugal summer, a little afternoon shade for the first few weeks helps them settle.

Watering and Mulching Rosemary

Young rosemary needs regular, deep watering through its first summer, especially plants grown from fresh cuttings. Water deeply, then let the top few centimeters dry out before watering again. Once the roots go deep, water needs drop dramatically, and established plants ride out long dry summers with little or no extra irrigation.

On our Quinta I've stopped watering our rosemary now, and I won't start again until April or May next year.

Winter is when you need to be careful. In rainy Mediterranean winters, stop watering completely and make sure water can drain away from the roots. Signs of trouble are yellowing lower leaves, a sudden collapse, or blackened stems at the base.

For mulch, keep it light. Gravel or small stones work beautifully because they reflect heat and keep the crown dry. If you use organic mulch, keep a clear gap around the stem so air can move.

We mulch ours mostly with dry grasses and anything else we can get our hands on.

Soil and Feeding Needs for Rosemary

Drainage matters far more than fertility. Rosemary is happy in sandy, rocky or loamy soil with a pH of roughly 6.0 to 8.0. On heavy clay, loosen the soil deeply and work in grit, gravel or coarse organic matter, or plant on a slight mound so winter rain runs off.

Don't feed it heavily. Overfed rosemary grows soft, floppy and less aromatic. Lean soil gives you tougher plants with a stronger scent. A thin layer of compost at planting is plenty for most gardens.

Pruning and Seasonal Care for Rosemary

Prune lightly after flowering to keep the plant bushy and stop it getting leggy. Cut back into green, leafy growth only. Rosemary rarely regrows well from old, bare woody stems, so a hard cut into old wood can leave a permanent gap.

You can harvest sprigs year round. For drying, cut stems before flowering and hang bundles upside down somewhere shaded and airy.

So far we mostly prune the one in our greenhouse, which needs a trim every year. That also gives us a chance to take cuttings, and we may take some from the more mature outdoor plants to propagate.

Rosemary cuttings rooting in jars of water. I take these when I prune the greenhouse plant or the outdoor bushes, and most root without any hormone.

Mature upright rosemary usually handles moderate frost in Zone 8a. Young plants and freshly rooted cuttings are more vulnerable in their first winters, so plant them where frost won't sit, or keep them in pots in a sheltered spot until spring.

Common Care Problems with Rosemary

Browning from the center: usually poor airflow, too much moisture, or old woody growth. Light annual pruning opens the plant up.

Sudden wilting or collapse: most often root rot from waterlogged or compacted soil.

Leggy, sparse growth: too much shade, too much feed, or no pruning.

Aphids or spider mites: occasional, especially on stressed plants in hot, dry spells. A strong spray of water usually handles them.

We've lost one so far, the plant on the shady side of the fence line. Too little sun, or something eating its roots, are the likely culprits.

Herman's Tough Kraut Fixes: How to Care for Rosemary Problems

Most rosemary trouble in a Mediterranean garden comes down to water, pruning and placement. Here are quick answers to the questions I hear most often about how to care for rosemary.

Q: Why is my rosemary turning brown?

A: Rosemary browning from the center is usually caused by poor airflow, excess moisture or aging wood. Thin it lightly after flowering and cut back on water.

Q: Does rosemary need watering in summer?

A: Young rosemary needs regular deep watering in its first summer. Established rosemary handles long dry summers with little or no extra water.

Q: Can rosemary survive frost?

A: Mature rosemary usually tolerates moderate frost in Zone 8a. Protect young rosemary and fresh cuttings through their first winters.

Final Thoughts on How to Care for Rosemary

Rosemary rewards a light hand. Our oldest plants have been in the ground for more than three years, have grown a little taller than 1 meter (3.3 feet) with very little maintenance, and now give us endless cuttings for new plants. Pick a sunny, free-draining spot, help young plants through their first summer, keep them dry in winter and prune lightly. Then mostly leave them alone. Rosemary pairs well with the other drought-tolerant herbs for dry soil, and if you're growing it on a balcony, the same rules apply to growing drought-tolerant plants in containers.

For the full plant profile, propagation notes and our photos, read our upright rosemary Plant Library entry.