How to Grow Rosemary

What rosemary needs to grow well

Rosemary (Salvia rosmarinus) is a Mediterranean herb that evolved in dry, rocky, sun-exposed hillsides. In US gardens, it thrives when given conditions that mirror its native habitat: full sun, fast-draining soil, and infrequent watering. It fails in shade, heavy clay, or consistently moist conditions.

This is the key to understanding why rosemary dies in so many American home gardens. The plant looks like a robust shrub and survives considerable neglect in Mediterranean climates. But US home garden conditions — clay soil, frequent irrigation, high humidity — are exactly what rosemary cannot handle. Root rot from overwatering in poor-draining soil is the cause of the vast majority of rosemary deaths in US gardens.

Give it the right site, and rosemary is one of the most durable, long-lived herbs you can grow. Plants in USDA Zones 7–11 live 10–20 years or more, eventually reaching 3–4 feet tall and wide. In the colder portions of its range (zones 6–7), it requires more attention to cold protection and variety selection, but it can still live for many years with the right care.

For companion planting guidance and herb garden layout, see our herb garden guide and rosemary plant care guide.

USDA zone guidance for growing rosemary

The line between zones 6 and 7 is the critical boundary for rosemary outdoor survival. In Nashville, Tennessee (zone 6b), standard rosemary varieties die in a typical winter. Cold-hardy ‘Arp’ — developed at the National Arboretum — survives zone 6 winters reliably when grown in raised beds with excellent drainage and some wind protection.

How to plant rosemary outdoors

Site selection

Full sun is non-negotiable. Rosemary needs at least 6 hours of direct sun per day, and 8+ hours produces the most flavorful, aromatic plants. In less sun, plants grow slowly, become leggy, and are more susceptible to disease.

Soil drainage is the other non-negotiable. Rosemary cannot tolerate wet feet. Choose a planting site that:

• Does not collect standing water after rain
• Has fast-draining sandy or loamy soil
• Has a slope or raised elevation if possible
• Has a pH of 6.0–7.0

Amending heavy soil:

• Add 20–30% coarse horticultural sand or perlite to clay soil in the planting hole
• Consider building a raised bed (6–10 inches above ground level) in clay-heavy areas
• Avoid planting near downspouts, lawn irrigation zones, or low spots that stay moist

In my zone 6b Nashville, Tennessee raised beds, I mix native soil 50/50 with coarse sand for rosemary planting areas. This produces the fast drainage that allows me to grow ‘Arp’ as a perennial — standard soil in my yard holds too much moisture.

Planting from nursery transplant

1. Purchase a rosemary plant from a garden center (April–May in most US zones after frost risk passes)
2. Dig a hole twice the width and same depth as the nursery pot
3. If soil is clay-heavy, amend with sand or perlite as described above
4. Remove the plant from the pot and loosen any circling roots
5. Plant at the same depth as it grew in the pot — planting too deep promotes stem rot
6. Water once to settle the soil
7. Do not water again until the soil is completely dry at 2-inch depth (typically 5–10 days)
8. Do not mulch with organic mulch immediately around the stem — keep a 3-inch gravel or bare zone at the base

Gravel mulch — 1–2 inches of pea gravel or coarse grit around the plant base — improves drainage and reduces moisture at the crown, the most rot-prone part of the plant.

Growing rosemary in containers

Container growing extends rosemary into every US climate zone, since pots can move indoors for winter in zones 3–6.

Container requirements:

• Terra cotta or unglazed ceramic pot (allows air and moisture exchange through pot walls)
• Drainage holes are mandatory — no exceptions
• Pot size: 12–16 inches for a standard herb garden plant; up to 18–24 inches for specimen plants
• Potting mix: cactus/succulent mix, or standard potting mix amended with 30% perlite or coarse sand

Watering container rosemary:

• Check soil every 4–5 days in summer
• Water only when the top 2 inches are completely dry
• Water thoroughly until water runs from drainage holes
• Empty saucer after 30 minutes — never let the pot sit in standing water

Container-grown rosemary dries faster than in-ground plants and may need water every 7–10 days in summer. In winter indoors, water every 2–3 weeks — indoor heating creates dry air, but the plant grows slowly and uses less water.

Growing rosemary indoors in winter

In zones 3–6, rosemary comes indoors before the first frost, typically October. Growing rosemary successfully indoors through a US winter is the most challenging aspect of keeping it as a long-term plant in cold climates.

The challenge: Rosemary indoors needs 6–8 hours of direct sun per day. In most US homes in winter (USDA zones 3–6), even south-facing windows provide only 3–5 hours of usable light on clear days, and cloudy days reduce this further.

Solutions:

• South-facing window: best natural light option; supplement with a grow light if the plant grows leggy or drops significant foliage
• Grow light supplement: place a full-spectrum LED grow light 6–10 inches above the rosemary and run 6–8 hours per day
• A grow light without a south window: 12–14 hours per day of full-spectrum LED is adequate for winter survival

Other indoor care:

• Keep away from heat registers that blast dry hot air
• Provide good air circulation — overhead fans or briefly opening a window on mild days reduces the fungal diseases that attack rosemary indoors
• Temperature: 55–65°F is ideal; can tolerate down to 40°F
• Misting is not recommended — rosemary prefers dry foliage; excess moisture on leaves promotes mildew

Harvesting rosemary

Harvest no more than one-third of the plant at one time. Rosemary cannot regenerate from bare woody stems the way many herbs can. Once a stem is cut back to the leafless woody portion, it will not produce new growth from that section.

Harvesting technique:

• Use clean, sharp scissors or pruning shears
• Cut soft green growth only — the new stem growth at the tips
• Leave at least two-thirds of the plant’s green growth intact
• Harvest in the morning after dew has dried for maximum oil content (most aromatic)
• Remove no more than 20% of the plant volume in any single harvest

When to harvest:

• Start when the plant has been in the ground at least 4–6 weeks and is actively growing
• Harvest year-round in zones 7–11
• Harvest through growing season (May–October) in zones 5–6; reduce or stop harvesting 6 weeks before expected first frost to allow new growth to harden

For preservation of your rosemary harvest, see our how to dry herbs guide.

Propagating rosemary from cuttings

Rosemary propagates easily from stem cuttings — faster than growing from seed and produces a true-to-parent plant. This is the best way to get additional plants for free.

Steps:

1. Take 4–6 inch tip cuttings from non-flowering new growth in spring or early summer
2. Remove leaves from the bottom 2 inches of the cutting
3. Dip the cut end in rooting hormone powder (optional but speeds root development)
4. Insert into well-draining rooting medium: perlite, coarse sand, or a 50/50 mix of perlite and potting mix
5. Keep moist but not wet (mist daily)
6. Roots develop in 3–6 weeks
7. Once roots are 1–2 inches long, transplant to a container with well-draining potting mix

Rooted cuttings overwinter well indoors and are ready for outdoor planting the following spring.

Common problems growing rosemary

Companion planting with rosemary

Rosemary is beneficial planted near brassicas (cabbage, broccoli, kale) — its strong scent deters cabbage moths and whiteflies. It also grows well alongside other drought-tolerant Mediterranean herbs including lavender, sage, and thyme, which share its preference for full sun and dry, well-drained conditions.

For additional herb growing guides see our how to grow cilantro guide and mint plant care guide.