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's hardy across USDA zones 10 through 11, 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
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Soil pH
- 4.3–8.2
- FAO ECOCROP
- Sun
- Full Sun
- Growable Ground Plant Database
- Days to Maturity
- 70 days
- Growable Ground Plant Database
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.
Zone averages can't see the slope, soil, frost, and sun that decide whether purple basil actually takes — and those shift from one yard to the next. Enter your address and we'll score purple basil against your land's real conditions.
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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.
How to grow Purple Basil
Purple Basil grows in USDA zones 10 through 11 and 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
USDA PHZM 2023
Soil pH
4.3 - 8.2
FAO ECOCROP
Sun
Full Sun
Growable Ground plant catalog
Drainage
well (dry spells)
Growable Ground plant catalog
Minimum Growing Temperature
44.6°F
Below this it stops growing rather than dies — a pace limit, not a survival limit.
Growable Ground Plant Database
Days to Maturity
70 days
Growable Ground plant catalog
GDD Required
1500+
Growing degree-days of accumulated warmth it needs to mature — humid summers reach this faster than cool coastal ones.
Growable Ground plant catalog
Mature Height
1.5 ft
Growable Ground plant catalog
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.
Match the soil
Purple Basil prefers pH 4.3 to 8.2 (FAO ECOCROP). 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
Purple Basil is ready about 70 days after planting. Snip sprigs as you need them — regular cutting keeps the foliage tender and slows it bolting to flower.
Where Purple Basil thrives
Purple Basil is hardy across USDA zones 10 through 11. 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 — and which side of that line your land sits on changes the answer.
Zones 10–11·Where Purple Basil growsOpen 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
Purple Basil’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
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
In rotation planning, purple basil counts as a Other — beds recover best when other crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Good to know
Good news for pet owners — purple basil isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Purple Basil offers moderate value to bees and other pollinators. (Source: Pollinator Partnership.)
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 9 federal source types across roughly 1.8M 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 exact soil pH, drainage, sun exposure, and frost dates shape whether purple basil 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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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•USDA PHZM•ASPCA
Frequently asked questions
Can I grow Purple Basil in my zone?
Purple Basil grows in USDA hardiness zones 10 through 11 (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 Purple Basil take to grow?
Purple Basil is ready to harvest about 70 days after planting. 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. 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 (FAO ECOCROP). Your report scores your parcel's actual 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. (Source: Pollinator Partnership.)
Is Purple Basil safe for pets?
Purple Basil is not known to be toxic to dogs or cats based on available data. Always supervise pets around new plantings. (Source: ASPCA.)