Rosemary Care Guide
Salvia rosmarinus (formerly Rosmarinus officinalis)
Quick Answer
Rosemary is more forgiving than most people expect, but consistent care makes a big difference. Water when the top 1–2 inches of soil are dry rather than on a fixed schedule, give it adequate light for its category, and feed lightly during the growing season. Catching problems early — a change in leaf colour or texture — is the key to keeping it healthy.
⭐Difficulty
Easy outdoors; Moderate indoors
☀️Light
Full sun to bright indirect
💧Watering
Every 7–10 days
🌫️Humidity
Low (30–40%)
🌡️Temperature
20–90°F
📈Growth Rate
Slow–Moderate
Toxicity
Source: ASPCA Animal Poison Control
Watering
Summer
Every 7–10 days
Winter
Every 10–14 days
Method: Allow to dry slightly between waterings; drought tolerant once established; excellent drainage essential; never waterlogged
In summer, aim to water rosemary approximately every 7–10 days; in winter cut back to around every 10–14 days. Rather than following a calendar, let the soil dry out completely — all the way to the bottom of the pot. Water thoroughly until water drains from the bottom, then don't water again until the soil passes the dryness check. Soft or mushy leaves signal overwatering; slight wrinkling or shrivelling means it's time to water.
Light Requirements
Full sun to bright indirect
Rosemary does best in a south- or west-facing windowsill where it gets at least 2–4 hours of direct sun. Without direct light, Rosemary stretches toward the light source, loses its compact shape, and colour or markings may fade.
Soil & Potting
Soil: Sandy, gritty, well-draining mix; cactus/herb blend
Pot: Terracotta with drainage; allows soil to dry and breathe
Temperature & Humidity
Temperature: 20–90°F (-7–32°C)
Humidity: Low (30–40%)
Fertilizing
Frequency: Once or twice in spring; minimal feeding
Type: Very diluted balanced fertilizer; excess fertilizer dilutes flavor
Common Problems
Powdery mildew
Powdery mildew: Low light + poor airflow indoors. Improve both; treat with diluted neem oil. Catching the problem early makes it much easier to fix — watch for early warning signs and act before the plant is in serious distress.
Root rot
Root rot: Overwatering. Gritty mix + terracotta + dry-between-waterings are essential. Check the roots: if they're dark, mushy, or smell off, root rot has set in. Unpot the plant, trim all affected roots with clean scissors, dust with cinnamon, and repot in fresh dry mix before resuming a cautious watering schedule.
Woody unproductive plant
Woody unproductive plant: Prune after spring flowering; take no more than one-third. Catching the problem early makes it much easier to fix — watch for early warning signs and act before the plant is in serious distress.
Dropping needles indoors
Dropping needles indoors: Shock from moving, or low light. Stabilize conditions; maximize light. Catching the problem early makes it much easier to fix — watch for early warning signs and act before the plant is in serious distress.
Propagation
The easiest way to propagate Rosemary is by stem cuttings. Take a 4–6 inch cutting that includes at least one node (the point where a leaf attaches). Remove any leaves that would be submerged, then place it in water or directly into moist potting mix. In water, roots appear within 2–4 weeks; pot up once they reach an inch long. The thing that trips people up most: taking a cutting without a node. Without a node, the cutting stays green for weeks but will never root.
Seasonal Care Calendar
🌸 Spring
Spring is when Rosemary starts actively pushing new growth as day length and light intensity increase. Increase watering frequency as the plant becomes more active, begin fertilising every 2–4 weeks with a balanced liquid fertiliser, and this is the ideal window for repotting or taking cuttings.
☀️ Summer
Summer is peak growing season — Rosemary is working hard and using water and nutrients faster than at other times of year. Water more frequently but check the soil rather than going on a fixed schedule, since heat and higher light accelerate drying. If you move it outdoors, introduce it to conditions gradually to prevent sun scorch.
🍂 Fall
Fall is a transition: Rosemary grows more slowly as light levels decrease. Reduce watering frequency slightly, stop fertilising by late October, and move it closer to a window to compensate for shorter days. Avoid drafts from opening windows as temperatures drop. Watch for flower buds developing around late winter–spring — avoid repotting or relocating the plant at this time.
❄️ Winter
In winter, Rosemary enters a slower-growth phase and uses water more slowly than in summer. Water less frequently to avoid root issues from soil staying wet too long in low light. If your home is heated and the air is dry, a pebble tray or humidifier keeps the plant comfortable.