Rosemary is a perennial culinary herb, grown for the flavor it brings to the kitchen, ready to harvest about 90 days after planting. It's hardy across USDA zones 8 through 10, stands up to deer and handles dry spells once it's established. Its summer flowers are a real draw for honeybees and native bees, even though the harvest is the prize.
Zones
8-10
pH Range
4.2-8.3
Sun
Full Sun
Days to Maturity
90
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What Rosemary is
Rosemary grows as a perennial and reaches around four feet at maturity. It blooms blue in summer. It's also deer-resistant.
How to grow Rosemary
Rosemary grows in USDA zones 8 through 10 and is ready to harvest about 90 days after planting. Rosemary does best in full sun — at least 6 hours of direct sun a day — and soil from pH 4.2 to 8.3, on well-drained ground. It needs around 2,500 growing degree days to mature and a growing season of at least 120 frost-free days, which is why climate matters as much as soil.
USDA Zones
8-10
USDA PHZM 2023
Soil pH
4.2 - 8.3
USDA PLANTS Database
Sun
Full Sun
plant_species_v5.csv
Drainage
well (dry spells)
plant_species_v5.csv
Frost Tolerance
41°F
plant_species_v5.csv
Days to Maturity
90 days
Rosemary; perennial in zone 7+; container in colder zones. Slow from seed; usually cutting.
UMD-Herb; RHS
GDD Required
2500+
plant_species_v5.csv
Mature Height
4 ft
plant_species_v5.csv
Frost-Free Days
120+
plant_species_v5.csv
Start the season right
Plant rosemary in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed.
Match the soil
Rosemary prefers pH 4.2 to 8.3 (USDA PLANTS Database). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Harvest at maturity
Rosemary is ready about 90 days after planting (UMD-Herb; RHS). Snip sprigs as you need them — regular cutting keeps the foliage tender and slows it bolting to flower.
Good to know
Good news for pet owners — rosemary isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Rosemary is a standout pollinator plant — high value to bees and other pollinators. (Source: Xerces Society, Pollinator Partnership.)
Where Rosemary thrives
Rosemary is hardy across USDA zones 8 through 10. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
Zones 8–10·Where Rosemary growsOpen map →
On USDA hardiness-zone overlap, Rosemary can grow in these states:
See if Rosemary will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether rosemary actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Frequently Asked Questions
Can I grow Rosemary in my zone?
Rosemary grows in USDA hardiness zones 8 through 10 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
How long does Rosemary take to grow?
Rosemary is ready to harvest about 90 days after planting (UMD-Herb; RHS). Your local frost dates and soil temperature move that window earlier or later.
When should you plant Rosemary?
Most growers plant rosemary after the last spring frost, once the soil has warmed, leaving enough of the season for its 120-day frost-free need. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Rosemary need?
Rosemary needs full sun — a spot that catches at least 6 hours of direct summer sun a day. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Rosemary need?
Rosemary prefers soil pH 4.2 to 8.3, on well-drained ground (USDA PLANTS Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Rosemary attract pollinators?
Yes — rosemary's flowers are a strong nectar and pollen source for honeybees and native bees (Xerces Society, Pollinator Partnership).
Is Rosemary safe for pets?
Rosemary is not known to be toxic to dogs or cats based on available data (ASPCA). Always supervise pets around new plantings.