When to plant rosemaryin Adelaide.

Growing rosemary in Adelaide: the specifics

Adelaide shares Perth's Mediterranean climate but with slightly cooler winters and a more distinct spring growing season. Hot, dry summers can exceed 40°C during heatwaves, while winters are mild with reliable rainfall. The Adelaide Hills just east of the city experience noticeably cooler conditions with light frosts, while the plains and coastal suburbs rarely frost. Spring and autumn are Adelaide's gardening goldilocks zones, warm enough for most vegetables, cool enough for quality harvests. For rosemary, the productive window in Adelaide is year-round. Within that window, Rosemary is best established from semi-hardwood cuttings rather than seed, cuttings root easily and produce a plant true to variety, whereas seed-grown rosemary is variable. Take 10-15cm cuttings from new growth in autumn or spring, strip the lower leaves, and insert into a free-draining propagating mix. Roots develop within 4-8 weeks. In raised beds, rosemary is best positioned as a permanent resident at one end of a long bed, its woody shrub habit and perennial nature means it will be there for years, and planning around it from the start avoids disruption. Rosemary demands free-draining soil above all else, it will rot in heavy, wet, or poorly drained conditions. The free-draining nature of raised beds makes them ideal for rosemary, especially in high-rainfall areas. Never overwater rosemary or allow it to sit in water. Once established, rosemary requires almost no care, a hard prune after flowering in spring to maintain shape and encourage fresh growth is the primary management task. Do not feed heavily; rich soil produces lush but less aromatic growth. Choose varieties for purpose: 'Prostrate Rosemary' is low-growing and cascades beautifully over bed edges; 'Tuscan Blue' and 'Miss Jessop's Upright' are tall and upright with excellent flavour; 'Blue Lagoon' is compact and suited to smaller beds.

Sizing it for your household

1 plant is more than sufficient for a family of 4; rosemary is rarely needed in large quantities Ongoing; an established rosemary bush can produce kilograms of fresh herb per year. Plant Planner does this maths automatically once you tell it your household size, it’s the part most planners get wrong because they assume every household is the same.

The 60 cm spacing (with 80 cm between rows) means a standard 1.2 m × 2.4 m raised bed in Adelaide can hold 6 rosemary plants at maximum density, though in practice you’ll want to mix companions in, so plan for roughly 60-70% of that.

Companion plants for Adelaide

Good companions for rosemary include Broccoli, Cabbage, Kale, Beans. In Adelaide’s mediterranean/temperate climate, these pairings reduce pest pressure and improve pollination. Keep rosemary away from Cucumber, Pumpkin, they fight for the same nutrients or attract shared pests.

Adelaide-specific tips

• Adelaide's extreme summer heatwaves (40°C+) can kill vegetable plants within hours, keep shadecloth on hand and water deeply the day before forecast heatwaves.
• The Adelaide Hills is its own microclimate, if you garden above 400m, treat your conditions more like Canberra and expect frosts from June to September.
• Adelaide's low summer rainfall means drip irrigation is essential, hand-watering raised beds in 38°C heat is exhausting and inefficient.

Common problems

Phytophthora root rot is the most serious problem, caused by waterlogged soil. Ensure excellent drainage, especially in clay-based gardens. Rosemary beetle is a minor pest that can defoliate plants, handpick adults and larvae. Powdery mildew occasionally affects plants in humid, shaded positions, increase sun exposure and improve airflow. Spittlebug (froghoppers) creates frothy masses on stems; wash off with water.

Harvest

Harvest rosemary by snipping green stem tips 10-15cm long. The woody stems below do not regrow well when cut, always harvest green, current-season growth. Rosemary can be harvested year-round in most Australian climates. For large harvests, prune up to one-third of the plant after flowering in spring.