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Basil
Ocimum basilicum
Basil is grown for its foliage rather than flowers, giving the garden structure and color all season long.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Basil
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 10–11. Expect it to reach about 20 in tall and 12 in wide at maturity, in roughly 1 year (not yet checked).
No toxicity note is on file for Basil. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Basil
Wait until all danger of frost has passed, then plant out Basil into warm soil; in most zones that means late spring.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 10, the middle of this plant's hardy range, start with zone 10 in January. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Basil get?
20 intall5 ft 7 inan adult12 inwideSee Basil in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Basil
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Basil about 12 in apart, center to center, so each plant has room to reach its full width.
Add Basil to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Basil's height, spread, hardiness zones, sun and trait tags were checked against 6 published sources on July 29, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Missouri Botanical Gardenheight, spread, hardiness zones, sun and trait tags
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun and trait tags
- Penn State Extensionheight, spread, sun and trait tags
- RHSRoyal Horticultural Societyheight, spread, sun and trait tags
- University of Illinois Extensionheight, sun and trait tags
- University of Florida IFASUF/IFAS Extension Pasco Countyhardiness zones and sun
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Basil
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Worth knowing
The aromatic oils that give basil its flavor are the same chemistry that deters deer and rabbits: the trait you grow it for is what protects it. per NC State and Clemson
How drought-tolerant is basil
Guides split: most say keep the soil evenly moist, while Iowa State says an established plant tolerates brief drying. Everyone agrees: even moisture, no waterlogging, watered at the base. per Iowa State and Clemson
Pinch flowers or let bloom
For leaves, pinch out every flower spike to keep foliage tender. But Penn State says let a few plants bloom for bees. You can do both in one bed. per Clemson and Penn State
Basil downy mildew
Now the crop's defining disease: yellowing leaves with fuzzy gray mold beneath. Fight it with resistant cultivars, wide spacing for air flow, and dry foliage. Infected leaves stay safe. per Minnesota
Frost kills it
Extremely cold-sensitive. Wait to plant out until nights stay above 50 F (10 C) and days reach the 70s F; even 50 F blackens leaves, and frost kills it. per Clemson
Mint family, no spreading
Despite being a mint relative, basil does not run and spread like true mints: no rhizomes or runners, just a tidy clump that reseeds only from flowers left to mature. per NC State
What pairs well with Basil
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Sunflower
Shares full sun and moderate water; its seed heads stand through winter, for structure and the birds; taller at 6.5 ft, for the layer behind it.
Pampas Grass
Shares full sun and low to moderate water; its seed heads stand through winter, for structure and the birds; taller at 8 ft, for the layer behind it; they only overlap in zones 10 to 11.
Gardenia
Takes full sun to part sun and moderate to high water; evergreen, so the bed keeps its shape through winter; taller at 4 ft, for the layer behind it; they only overlap in zones 10 to 11.
Agave
Shares full sun and low to moderate water; evergreen, so the bed keeps its shape through winter; they only overlap in zones 10 to 11.
Rosemary
Shares full sun and low to moderate water; evergreen, so the bed keeps its shape through winter; taller at 3.5 ft, for the layer behind it; they only overlap in zone 10.
Black-Eyed Susan Vine
Shares full sun and moderate water; climbs to 8 ft behind it, height without the footprint; they only overlap in zones 10 to 11.
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.