Rosemary
Salvia rosmarinus
Herb
- Light
- Sunny
- Pot size
- Medium pot (about 5 to 15 litres)
- Care level
- Moderate
- Year round or seasonal
- Kept year to year; cold-hardy in the ground to about −12.2 °C (10 °F)
- Pets
- ASPCA: non-toxic to cats and dogs
Light and position
Full sun.
Size and pot
A shrub that NC State lists at 4 to 5 feet; it suits containers. Our pot band: medium pot (about 5 to 15 litres).
Watering
Drought tolerant. NC State says overwatering is the most common reason it declines or dies.
Potting mix and feeding
Very well-drained mix. NC State notes low tolerance of wet, humid conditions; poor air flow and high humidity bring powdery mildew, so give it extra air and sun through a humid monsoon.
Growing through the year
Stem cuttings are more reliable than seed, which is slow to germinate.
Winter outdoors
Cold-hardy in the ground to about −12.2 °C (10 °F). NC State lists USDA zones 8a to 10b, and its container chapter names rosemary among herbs that tolerate cold weather and can overwinter outside in the pot, ideally near the house or in a sheltered spot. The lower edge of zone 8a, 10 °F, describes plants in the ground, so we do not rate a pot below −5 °C.
| Your coldest winter nights | What to do |
|---|---|
| Coldest nights 15 °C or warmer | Can stay out through this winter |
| Coldest nights 10 to 15 °C | Can stay out through this winter |
| Coldest nights 5 to 10 °C | Can stay out through this winter |
| Coldest nights 0 to 5 °C | Can stay out; wrap the pot or move it to a sheltered spot in freezing weather |
| Light frost: nights down to about −5 °C | Can stay out; wrap the pot or move it to a sheltered spot in freezing weather |
| Hard frost: nights below −5 °C | Shelter it or insulate the pot: we do not rate any potted plant for nights below −5 °C |
A plant can stay out only when its limit is below the coldest night in your band; a limit equal to that night counts as needing shelter. A rare cold snap, wind or a wet pot can still damage plants. USDA describes hardiness zones as general guides based on average yearly lowest temperatures, and they describe plants in the ground. NC State warns that roots in a container are not as well insulated from cold as roots in the ground, and suggests wrapping pots or moving them to a sheltered spot. We convert °F to °C with NIST’s formula.
Watch for
Aphids, mealybugs, whiteflies and spider mites; powdery mildew and root rot.
Pets and people
ASPCA lists rosemary as non-toxic to dogs, cats and horses.
General gardening information, not professional advice. Plant toxicity details are a starting point, not veterinary or medical advice: if a pet or child may have eaten a plant, contact a veterinarian or doctor promptly.
Care level: NC State’s maintenance rating (Medium). Pot band and summary wording are ours, based on the sources below.