Rosemary
Sources last read 14 September 2026.
Forgiving Among the more tolerant plants here.
Also called Anthos, old man, rose of the sea and southernwood.
Rosemary is toxic
What the sources say about its care
Sources file this plant under other names: Rosmarinus officinalis (ASPCA). Citations below point at the name its source uses.
- Light
- Full sunRHS · read 13 September 2026
- Water
- Well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H4 — -10 to -5°C -10 to -5 °CRHS · read 13 September 2026- Soil
- Chalk, Loam, Sand; pH Acid or Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- Listed as non-toxicASPCA, filed as Rosmarinus officinalis · read 13 September 2026
- Toxic to dogs
- Listed as non-toxicASPCA, filed as Rosmarinus officinalis · read 13 September 2026
- Harmful to people
- Can cause skin allergy. Use gloves and protective gear when handling it.RHS · read 13 September 2026
How it usually goes wrong
- Crisp margins that appear in winter
A yellow halo sits just inside the brown edge on the rosemary, and new leaves often come in already tipped with brown during the heating season.
The edges fail first because they are the end of the plumbing. Penn State Extension cites 30% to 60% as the recommended indoor range, and winter heating regularly takes a room under it. That applies while it is grown indoors; its RHS rating of H4 describes a plant that also grows outside, where the air is seldom that dry.
Telling it apart: What else in the room changed. Edges that browned when the radiators came on point at the air rather than at the watering.
Penn State ExtensionRosemary brown leaf tips and edges: causes- Dry scorched spots after a move into a sunnier spot
On a rosemary the scorch appears within a few days of a sunny spell or a move, and it does not spread afterward.
Nothing here disputes the full sun its source names. The damage comes from the change: foliage formed in lower light is thin, and a sudden move into direct sun bleaches it faster than tougher growth can replace it.
Telling it apart: Whether the patches grow. Scorch is done once it happens; a leaf spot keeps spreading.
RHSRosemary spots on leaves: causes- Flowering stops while the foliage carries on
The rosemary looks well in every other respect: green, firm and growing. What is missing is the flowering.
Buds are formed only when the plant has energy to spare. Its source places it in full sun, and in less light than that the surplus that pays for flowers is missing.
Telling it apart: Whether the stems have stretched. Leafy, stretched growth with no buds points at light; normal spacing points at timing, feeding or a season it has not had.
RHSDiagnose no flowers or dropped buds on this Rosemary- Leaves bruised and browned along the edges after a gale
The rosemary looks battered rather than sick. Leaves are nicked and browned at the edges, and the damage is heaviest on the most exposed side.
Its source describes a sheltered spot. In an exposed one, wind both dries the leaves and damages them physically, which is why the marks follow the direction of the weather.
Telling it apart: Which side. Wind marks the side facing it; dry soil marks the whole plant.
RHSRosemary brown leaf tips and edges: causes- The plant goes limp and the compost shrinks from the pot
Leaves on the rosemary turn dull and soft before any colour changes, and water poured on the dry surface runs straight down the inside of the pot.
With well-drained soil taken past dry, there is nothing left for the roots to move, and the plant gives up its shape before it gives up its colour.
Telling it apart: Whether the soil has pulled from the pot wall. That gap is the mark of soil taken properly dry.
RHSDiagnose drooping on this Rosemary
Not sure which it is? Ask the diagnosis questions for Rosemary.
Routine care
- Propagation
- Rosemary seed is slow to germinate, so stem cuttings, layering or division may give better results.NC State Extension · read 13 September 2026In spring sow seed in pots or trays in a cold frame, or in summer take semi-ripe cuttings.RHS · read 13 September 2026
- Pruning
- It copes with drought, partial shade, salt, hard pruning and most soils apart from clay. After flowering, it can be cut back hard to promote dense foliage.NC State Extension · read 13 September 2026Pruning group 9; trim hedges once flowering ends.RHS · read 13 September 2026
- Pests and diseases
- Can be troubled by aphids. Diseases: southern blight.NC State Extension · read 13 September 2026Can be troubled by scale insects, tortrix moth, sage leafhopper, cuckoo spit and rosemary beetle. Diseases: foot and root rots, Verticillium wilt, powdery mildews and, rarely, honey fungus.RHS · read 13 September 2026
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Photographs
About the plant
Salvia rosmarinus, synonym Rosmarinus officinalis, commonly known as rosemary, is a shrub with fragrant, evergreen, needle-like leaves and purple or sometimes white, pink, or blue flowers. It is a member of the mint family, Lamiaceae. The species is native to the Mediterranean region. It has numerous cultivars, and its leaves are commonly used as a flavoring.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- Medit.World Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Africa, Europe, Western Asia, MediterraneanNC State Extension · read 13 September 2026MediterraneanRHS · read 13 September 2026
- Climate
- temperateWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- Herb, Perennial, Shrub; habit arching, columnar, erect, irregular, rounded, spreadingNC State Extension · read 13 September 2026Bushy (evergreen)RHS · read 13 September 2026
- Size
- Height 48–60 in; width 36–48 inNC State Extension · read 13 September 2026Height 1.5-2.5 metres; spread 1.5-2.5 metres after 5–10 yearsRHS · read 13 September 2026
- Flowering
- Flowers blue, purple/lavender, white; blooms in spring, summerNC State Extension · read 13 September 2026Flowers blue in spring and summer; purple in spring and summer; white in spring and summerRHS · read 13 September 2026
- Uses
What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.
The strongly scented leaves of this shrub are often gathered for cooking, potpourri and other uses. Its oil is used commercially in some perfumes, shampoos, soaps, lotions and toiletries. Ancient Greeks and Romans tossed sprigs into graves to show they wished to remember the dead. In Ancient Greece it was also thought to improve memory, and students studied with sprigs worn in their hair. Used in teas and to flavor jam, vinegar, butter, bread, stuffing, vegetables, stews and meat, and, combined with other herbs and salt, to season most dishes.NC State Extension · read 13 September 2026
Common problems with Rosemary
More of the Lamiaceae family
English lavenderBuds form and fall before they open
Sweet basilA thin dry rim that crumbles between the fingers
Caribbean OreganoSourced care, difficulty not yet judged
ColeusSourced care, difficulty not yet judged
- No photograph yetColeus thyrsoideusSourced care, difficulty not yet judged
Plectranthus oertendahliiSourced care, difficulty not yet judged
Plants with similar care
Blue passion flowerA thin dry rim that crumbles between the fingers
Bush lilyDry, curled edges on leaves near a heater
Dog roseEdges of the leaves brown while the middle stays sound
Flaming KatyA thin dry rim that crumbles between the fingers
Hardy fuchsiaBrown, papery patches on the leaves nearest the glass
HyacinthFlowering stops while the foliage carries on
Sources
- ASPCA · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.