How to Care for Rosemary

Rosemary (Salvia rosmarinus) is a woody, needle-leaved Mediterranean evergreen prized for its silvery-green foliage and sky-blue flowers. It is an easy, drought-tolerant shrub as long as you give it strong light and never let it sit in wet soil.

Light

Rosemary demands full sun — aim for at least six to eight hours of direct light daily. Outdoors, give it your brightest, most open spot. Indoors it is far fussier: place it directly against your sunniest south- or west-facing window, and supplement with a grow light in winter, since weak light causes thin, floppy, mildew-prone growth.

Water

Keep watering low and let the soil dry substantially between drinks. Water deeply, then wait until the top inch or two of soil is dry before watering again. Rosemary far prefers to run dry than to stay soggy; chronic overwatering and poor drainage are the most common ways it declines. In containers, always empty the saucer so roots never stand in water.

Soil & Potting

Use a lean, gritty, sharply draining mix. A cactus or Mediterranean-herb blend cut with extra perlite, pumice, or coarse sand works well. Rosemary tolerates poor, rocky soil and prefers a neutral to slightly alkaline pH. Always plant in a container with generous drainage holes — unglazed terracotta is ideal because it wicks moisture away from the roots.

Humidity & Temperature

Rosemary likes warm days and dry air, and resents humid, stagnant conditions that invite mildew. Give it good airflow at all times. It handles heat easily and tolerates mild frost once established, though hardiness varies by cultivar; in cold-winter climates grow it in a pot you can move to a bright, cool, frost-free spot indoors.

Feeding

This is a light feeder that actually performs best in lean soil. A single light dose of balanced, diluted fertilizer in spring is plenty for garden plants. Container specimens can be fed a weak liquid feed once a month during active spring and summer growth. Avoid heavy nitrogen, which produces soft, weak, less aromatic growth.

Propagation

Rosemary roots readily from stem cuttings. Take four-inch tip cuttings from semi-woody growth, strip the lower leaves, and insert into moist, gritty mix; keep lightly damp with good airflow and roots form in a few weeks. You can also layer a low branch by pinning it to the soil until it roots. Seed is slow and unreliable, so cuttings are the preferred method.

Repotting / Pruning

Repot container plants every year or two into the next size up, refreshing the gritty mix. Prune lightly and often to keep the plant bushy — pinch or trim the soft green tips after flowering to encourage branching. Avoid cutting hard back into old, bare wood, as rosemary is slow or unwilling to resprout from leafless woody stems.

Common Problems & Pests

Root rot from overwatering and powdery mildew from humid, still air are the two main threats — both are prevented by dry soil and strong airflow. Indoors, watch for spider mites and aphids on tender new growth; rinse them off or treat with insecticidal soap. Yellowing lower needles usually signal soggy roots, while brown, crispy tips point to underwatering or scorching.

Seasonal Care Tips

Spring is the time to prune, feed lightly, and repot as new growth resumes. Through summer, water deeply but infrequently and enjoy the flush of flowers. In autumn, taper watering and, in cold regions, bring potted plants into a bright, cool room before hard frost. In winter, keep it cool, dry-ish, and in the brightest possible light to prevent leggy, mildew-prone growth.