Purple Basil is an annual or perennial culinary herb, grown for the flavor it brings to the kitchen, ready to harvest about 70 days after planting. It overwinters in USDA zones 10 through 11 and is grown as a summer annual wherever the season is long enough. Notably, it stands up to deer and grows just as well in a container as in the ground. Its summer flowers are a moderate draw for honeybees and native bees, even though the harvest is the prize.
Purple Basil — the short answer
Purple Basil: grown in zones 10–11, full sun, pH 4.3–8.2, about 70 days to maturity.
- USDA zones
- 10–11
- Not verified
- Soil pH
- 4.3–8.2
- We haven't confirmed this against a published source yet.
- Sun
- Full Sun
- We haven't confirmed this against a published source yet.
- Days to Maturity
- 70 days
- We haven't confirmed this against a published source yet.
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
Score Purple Basil on your exact land.
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See Purple Basil
What Purple Basil is
Purple Basil grows as an annual or perennial and reaches around a foot and a half at maturity. It blooms pink in summer. It's also deer-resistant and well suited to containers.
Life cycle, mature height, bloom period, flower colour, deer resistance and container suitability: We haven't confirmed this against a published source yet.
How to grow Purple Basil
Purple Basil overwinters in USDA zones 10 through 11 and is grown as a summer annual wherever the season is long enough; it is ready to harvest about 70 days after planting. Purple Basil does best in full sun — at least 6 hours of direct sun a day — and soil from pH 4.3 to 8.2, on well-drained ground. It needs around 1,500 growing degree days to mature and a growing season of at least 80 frost-free days, which is why climate matters as much as soil.
USDA Zones
10-11
Not verified
Soil pH
4.3 - 8.2
We haven't confirmed this against a published source yet.
Sun
Full Sun
We haven't confirmed this against a published source yet.
Drainage
well (dry spells)
We haven't confirmed this against a published source yet.
Minimum Growing Temperature
44.6°F
Below this it stops growing rather than dies — a pace limit, not a survival limit.
We haven't confirmed this against a published source yet.
Days to Maturity
70 days
We haven't confirmed this against a published source yet.
GDD Required
1500+
Growing degree-days of accumulated warmth it needs to mature — humid summers reach this faster than cool coastal ones.
We haven't confirmed this against a published source yet.
Mature Height
1.5 ft
We haven't confirmed this against a published source yet.
Frost-Free Days
80+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
Start the season right
Plant purple basil in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed. We haven't confirmed this against a published source yet.
Match the soil
Purple Basil prefers pH 4.3 to 8.2. We haven't confirmed this against a published source yet. 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. We haven't confirmed this against a published source yet. A 2–3 inch mulch layer holds moisture without waterlogging.
Harvest at maturity
Purple Basil is ready about 70 days after planting. We haven't confirmed this against a published source yet. Snip sprigs as you need them — regular cutting keeps the foliage tender and slows it bolting to flower.
Where Purple Basil thrives
Purple Basil overwinters in USDA zones 10 through 11 and is grown as a summer annual wherever the season is long enough. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 10–11 spans average winter lows from 30°F to 50°F (USDA PHZM 2023). Across the 50 states and DC, that band covers none outright but splits 8 down the middle.
Zones 10–11·Hardiness bandOpen map →
This map is derived from the USDA ARS / PRISM Plant Hardiness Zone Map (2023) and is not the official USDA Plant Hardiness Zone Map.
Where Purple Basil stands, state by state
Purple Basil is rated for zones 10–11 — a cold floor USDA puts at 30 to 40°F. Across the 50 states and DC, 0 sit fully inside that band, the line runs through 8 more, and 43 sit outside it — and inside every split state, the same line runs on at county grain.
The line runs through
8 states
- California · zones 4b-11a
- Nevada · zones 4a-10a
- Arizona · zones 5b-10b
3 of 8 shown
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Purple Basil
Growing guides for purple basil
Good to know
Listed as non-toxic to dogs and cats by a source we can't cite. We haven't confirmed this against a published source yet.
Purple Basil offers moderate value to bees and other pollinators. We haven't confirmed this against a published source yet.
Before you harvest purple basil, know your soil
Anything you grow to eat takes up what's in the ground it grows in, so it's worth knowing what's documented near you before you plant purple basil for food. Our free screen reads 8 federal source types across roughly 950K indexed sites and shows which sit near your address and which way they drain. It's a screening estimate from public records and proximity — not a soil test — so a nearby record means a soil test is worth it, not that your soil is unsafe.
Your land is one point inside Purple Basil's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
See if Purple Basil will thrive on your land
Zone averages are a start. Your soil pH, drainage, sun exposure, and frost dates shape whether purple basil actually takes. We score it against the mapped and modelled 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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How we know this about Purple Basil
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database
Frequently asked questions
Can I grow Purple Basil in my zone?
Purple Basil overwinters in USDA hardiness zones 10 through 11 and is grown as a summer annual wherever the season is long enough. Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
How long does Purple Basil take to grow?
Purple Basil is ready to harvest about 70 days after planting. We haven't confirmed this against a published source yet. Your local frost dates and soil temperature move that window earlier or later.
When should you plant Purple Basil?
Most growers plant purple basil after the last spring frost, once the soil has warmed, leaving enough of the season for its 80-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 Purple Basil need?
Purple Basil needs full sun — a spot that catches at least 6 hours of direct summer sun a day. We haven't confirmed this against a published source yet. 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 Purple Basil need?
Purple Basil prefers soil pH 4.3 to 8.2, on well-drained ground. We haven't confirmed this against a published source yet. Your report scores your parcel's mapped soil against that using USDA SSURGO data.
Does Purple Basil attract pollinators?
Yes — purple basil's flowers are a solid nectar source for honeybees and native bees. We haven't confirmed this against a published source yet.