Herb · Lamiaceae
Rosemary
Salvia rosmarinus
Set it in bright sun and gritty, fast-draining soil, water it now and then, and this easygoing Mediterranean herb rewards you for years.
Full sun
Every 7–14 days
USDA 7–11
2–6 ft · 0.6–1.8 m
Overview
If you have worried that herbs are fussy, rosemary is a lovely place to begin. This woody evergreen comes from the warm, dry hillsides of the Mediterranean, and it carries those easygoing habits with it. It sits in the mint family, yet unlike its thirsty cousins it would far rather stay lean and sunny than rich and damp.
Give it a good home and rosemary settles in as a perennial that returns year after year, slowly building woody stems dressed in narrow, needle-like leaves. Small blue flowers, and now and then pink or white ones, open from late winter into spring. In zones 7 through 11 it can live outside all year, and if your winters run colder, a pot you carry indoors keeps it content.
Here is the reassuring part: rosemary forgives far more than it punishes. The most common mistake is simply loving it with too much water, so if you tend to fuss, this is the plant that teaches a gentler hand. Keep the soil lean, water only when it has dried, and you will find there is very little that can go wrong.
Care
The short version: give rosemary all the sun it can get and soil that drains fast, then water only after it has dried well down. Feed it lightly if at all, leave room for air to move around it, and let it stay on the dry side through the year.
Light
Rosemary loves full sun, and the more it gets the happier it looks, ideally 6 to 8 hours a day. It will get by in part shade, but the growth turns thin and leggy and the flavor quietly fades. Indoors, simply set it in the brightest window you have and it will thank you.
Water
Watering is the one place a kind gardener can go wrong, so go easy here. Let the top half of the soil dry out before you water again, which usually lands around every 7 to 14 days, and water even less once the plant has settled in. When you are unsure, waiting is almost always the safe and forgiving choice.
Soil
Rosemary is happiest in light, sandy soil that drains fast. It takes poor and rocky ground in stride and asks for very little, but heavy clay holds too much water, so mix in some grit or sand if your soil stays wet. A pH of 6.5 to 7.0, close to neutral, suits it nicely.
Temperature
Rosemary copes with a wide swing in temperature, from about 10°F to 86°F (-12°C to 30°C), though how much cold it takes depends on the cultivar. A hard freeze can be too much for the tender types, so in cold areas choose a hardy one or bring pots indoors for winter, and you have nothing to fear.
Humidity
Coming from dry country, rosemary is content with low humidity, around 30% to 50%. Damp, still air is what invites powdery mildew, so gentle airflow does far more good than any misting or moisture you might be tempted to add.
Feeding
Rosemary is a light feeder that actually tastes better when kept a touch hungry. One gentle helping of balanced fertilizer or compost in spring is all it needs for the year. Give it much more and you trade its lovely fragrance for soft, sappy growth, so less really is kinder here.
Pruning
Trim lightly after it flowers and snip sprigs through the season, and the plant stays full and shapely without any fuss. Just keep to one gentle rule: avoid cutting back into old leafless wood, which is slow to sprout again and may not return, so stay in the green, leafy growth.
Repotting
Move a potted rosemary up a size every 1 to 2 years, or sooner if roots start circling the pot, water rushes straight through, or new growth stalls. A gritty, fast-draining mix and a pot with real drainage holes will keep its roots comfortable and dry.
Size & spacing
24–71 in (60–180 cm) tall
When to plant
Rosemary keeps its own slow schedule, and that is perfectly fine. Seed started indoors in late winter can be unpredictable, so many gardeners find it easier to set out young plants once spring frosts have passed. In mild climates you can gather sprigs all year, and those small blue flowers open from late winter into spring.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 10-12 weeks before last spring frost (germination is slow and erratic)
- Plant: after danger of frost has passed in spring
- Harvest: Small blue (occasionally pink or white) flowers in late winter to spring; leafy sprigs can be harvested year-round in mild climates.
Hardiness
USDA hardiness zones: 7–11
Temperature: down to -18°C
Troubleshooting
Nearly every rosemary worry comes down to one of two things: a little too much water at the roots, or not quite enough air around the leaves. The good news is that the early signs are easy to read, and catching them soon usually means an easy fix. Find your plant's symptom below and step in gently while it still helps.
A plant wilting and yellowing even while the soil stays wet
When rosemary sags in soggy soil, thirst is not the problem: this is root rot from overwatering or poor drainage. If you dig down gently you will find soft, brown roots with a sour smell. Ease off the water, repot into a gritty, fast-draining mix, and take a few healthy cuttings as a comforting backup in case this plant does not pull through.
Fix:
- Stop watering and allow soil to dry
- Repot into fast-draining gritty mix and trim rotted roots
- Take healthy stem cuttings as a backup if the plant is failing
Fine webbing and a tired, speckled look on the leaves
Faint webbing and pale speckling usually mean spider mites, which trouble indoor and stressed plants most in dry winter air. Turn a leaf over and you may catch the tiny mites moving among the threads. Rinse the foliage well, follow with insecticidal soap or horticultural oil, and give the plant more air, and it will bounce back.
Fix:
- Rinse foliage with a strong stream of water
- Apply insecticidal soap or horticultural oil
- Increase airflow and reduce plant stress
Brittle brown stems dropping their leaves after a hard winter
Bare, snapping wood after a cold spell is winterkill, and it falls hardest on tender cultivars in borderline zones. To tell living from dead, scratch the bark: green underneath means life, dry and brown means the stem is gone. Trim the dead stems back to living tissue in spring and let the plant push fresh growth from all that survived.
Fix:
- Prune out dead wood back to living tissue in spring
- Allow plant to regrow from healthy stems
A dusty white film settling over the leaves
That powdery coating is powdery mildew, a fungus that moves in when the air around the plant goes still. It tends to visit crowded indoor rosemary in stale winter air, so it is nothing to panic over. Open up the spacing, let the humidity drop, and pinch off the worst of the coated leaves, and the plant recovers.
Fix:
- Improve air circulation and spacing
- Reduce humidity and avoid overhead watering
- Remove and discard affected foliage
Toxicity
If you share your home with pets or little ones, you can relax with rosemary: it is non-toxic right across the board. The ASPCA lists it as safe for cats, dogs, and horses, and the very same culinary herb is fine on your own plate. The only thing to store away is the concentrated essential oil, a separate product that is not meant for eating.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Rosemary is gentle and safe for cats, and the ASPCA counts it among its non-toxic plants. A curious nibble does no harm at all, though most cats are not much taken with the strong scent anyway.
Dogs None
Dogs can chew the leaves with no trouble, and the herb even shows up in some pet foods as a natural preservative. Only a really large helping might bring on a mild, passing bit of stomach upset.
Horses Safe
Horses can graze rosemary in complete safety. The aromatic foliage is not a favorite of theirs, so they rarely take more than a taste.
Rabbits Safe
A little fresh rosemary is fine for rabbits as part of a varied diet. Hay and leafy greens should still make up the bulk of their meals, with the herb as a small extra.
Livestock Safe
Goats, sheep, and cattle can browse rosemary with no ill effect at all. The pungent leaves tend to keep most stock from eating much of it anyway.
Birds Safe
The herb is no danger to backyard hens or pet birds. A sprig in the run is quite harmless, even if it usually goes ignored.
People Safe
Rosemary is a kitchen favorite, safe to cook with and enjoy for adults and children alike. The one thing to keep separate is the concentrated essential oil, a different product that is not for eating.
Highly concentrated rosemary essential oil is a separate product that can irritate skin or be harmful if ingested in quantity, but the culinary herb and growing plant are non-toxic.
Varieties
Rosemary shows up in several shapes, from low mats that trail over an edge to tall, upright shrubs. A few cultivars are worth knowing when you are choosing one for a cold garden or for the kitchen.
Arp
One of the most cold-hardy cultivars there is, happy to ride out winters that would set back most rosemary.
Hill Hardy
An upright, cold-tolerant selection that keeps going in marginal northern gardens where a lot of rosemary would give up.
Tuscan Blue
A strong, upright grower with deep blue flowers, loved both for the kitchen and for clipping into low, tidy hedges.
Prostratus
A low, trailing groundcover type that spills softly over walls and pots, though it takes cold less kindly than the upright forms.
How to propagate
Stem cuttingsEasy
Spring to summer from softwood or semi-ripe growth · 4-8 weeks to root
Cuttings are the friendliest way to make more rosemary, and they are what most gardeners happily rely on. In spring or summer, take 8 to 15 cm pieces of soft or half-ripe growth, strip the lower leaves, and settle them into a gritty, well-drained mix, where they quietly root in 4 to 8 weeks.
SeedDemanding
Indoors 10-12 weeks before last frost · Several weeks to germinate, then a full season to establish
Growing from seed asks for patience, so do not feel discouraged if it is slow. Sow indoors 10 to 12 weeks before the last frost and expect scattered, unhurried sprouting and a modest strike rate, with weeks to germinate and a full season before plants truly establish. It is simply why most growers reach for cuttings instead.
Myths
Rosemary needs frequent watering to stay healthy.
Once it has found its feet, rosemary shrugs off dry spells and wants only a little water now and then. Far more plants are lost to soggy soil than to a missed watering, so a gentle, sparing hand is exactly the right instinct.
The rosemary plant is toxic to pets because rosemary oil can be harmful.
You can set that worry down. The ASPCA lists the growing plant and culinary herb as non-toxic to cats, dogs, and horses. Only the concentrated essential oil, which is a separate product, carries any irritation risk, and that is simply not what a pet meets in the garden or on the plate.