Basil planting dates by zone

When to plant basil

University of Minnesota Extension calls basil a tender annual: sow seed directly into the ground after the danger of spring frost has passed, or sow indoors six to eight weeks before planting outside. The table above counts both from your zone’s median last spring freeze, and gives NOAA’s one-year-in-ten date for a reader who would rather wait.

The sources give different lead times for starting seed indoors: six to eight weeks (Minnesota), six weeks (Penn State Extension), four to six weeks (Clemson’s Home & Garden Information Center), and three to four weeks to grow transplants for setting out well after the frost-free date (University of Illinois Extension). Penn State and Clemson both wait for warm days and warm nights before setting plants out, not just for the frost date.

If a late frost threatens after planting, Clemson covers basil with pine straw, inverted pots or buckets until it warms the next day.

Basil in the South

UF/IFAS Gardening Solutions says basil grows well in Florida’s warm climate: plant it from seed in either early spring or fall, in sun with a bit of afternoon shade to protect it from the heat. Most basils are annuals in Florida, but a few behave as perennials, and the plants are sensitive to frost, so protect them on cold nights. UF/IFAS Pinellas County says to sow seed every few weeks for a steady supply.

Texas A&M’s Growing Herbs in Texas trims basil often to keep it bushy, spaces plants 12 inches apart, and grows it in protected sun, well-drained soil and raised beds.

Sun, soil, water and feeding

Minnesota gives basil at least six to eight hours of bright light a day in well-drained soil with a pH of 6.0 to 7.5, fertilizes sparingly, and waters deeply every seven to ten days, more often in containers. Illinois says basil likes fertile soil well supplied with organic matter and to be kept well watered; poor soils give slow-growing basil without much flavor.

Clemson says not to over-fertilize, because the leaves lose flavor during rapid growth. It mulches 3 inches deep with pine needles or ground-up leaves and waters at the base of the plants, by soaker hose, drip or hand, without wetting the foliage, which makes it more prone to disease.

Pinching and harvesting for the kitchen

Minnesota says to harvest at any time by snipping young leaves as needed; when cutting whole stems, cut just above a pair of leaves, and new growth should show at the cut within a week. It says to prune periodically, because basil allowed to flower and set seed becomes woody, yields considerably less, and turns more bitter.

Penn State pinches out growing tips to hold off flowering and promote branching, harvests before flowers bloom, preferably in the morning, and says leaf flavor declines after bloom. Illinois pinches out flower buds as soon as they form. Clemson says to leave enough foliage on each plant after harvest that its growth is not much reduced, and not to harvest in wet weather.

For the kitchen, Illinois says basil picked for use is best held in a glass of water at room temperature, and that the refrigerator discolors the leaves; Penn State keeps cut stems a few days in water at room temperature, or up to a week in the refrigerator in a plastic bag wrapped in a paper towel.

At the end of the season

Clemson says the first fall frost kills basil, and the table above gives your zone’s median date. Before that frost, Clemson cuts plants back, digs up the roots and pots them for a sunny window indoors, watering regularly without letting them stand in water. Minnesota says indoor plants need plenty of bright light, possibly from lights run 10 to 12 hours a day, and that as annuals they will flower and die eventually, even indoors.

Illinois grows basil as a windowsill herb for fall, winter and early spring: sow several seeds in a small pot in full sun, start harvesting in about 4 to 5 weeks, and sow again every two weeks. Texas A&M names basil among the herbs best adapted to growing in pots indoors in winter.

Downy mildew and other problems

Minnesota says basil downy mildew is the most common basil problem there: it causes fluffy growth on the undersides of leaves and can kill whole plants, so choose a resistant variety. Penn State says the disease has been in the United States since 2007, appears as yellowing leaves with downy spores underneath, cannot overwinter, and returns on infected seed, transplants or wind-blown spores; discard infected plants and keep them out of the compost.

UF/IFAS says downy mildew is hard to recognize because its yellowing resembles a nutrient deficiency; the tell-tale sign is spores on the undersides of leaves, best scouted for early in the morning. It says all sweet basils are very susceptible, while red types, Thai, lemon, lime and other spicy basils are less so. UF/IFAS Duval County says UF plant breeder David Clark developed ‘Amazel’ basil, a downy mildew resistant variety.

Clemson says downy mildew spreads fast in mild, humid summers and is held back by keeping leaves dry: drip irrigation or soaker hoses, a very sunny site, plants spaced so their leaves dry quickly, and rotating where basil grows each year. It also describes Fusarium wilt, for which it recommends resistant varieties such as ‘Nufar’; gray mold, which enters stem cuts made in wet weather; and bacterial wilt, so it does not plant basil where tomatoes have died of it. Its most common pests are Japanese beetles, slugs and aphids.

Texas A&M’s survey of Texas herb crops names Japanese beetle as a pest of commercial basil, and Botrytis, leaf and Sclerotinia blights and Fusarium wilt as its diseases.

Common mistakes

• Planting out before the frost date has passed. Minnesota says to wait until the danger of spring frost is over, and Clemson that the first fall frost kills it.
• Letting it flower. Minnesota says basil that flowers becomes woody, yields less and turns bitter.
• Feeding it hard. Clemson says rapid growth from too much fertilizer costs the leaves flavor.
• Watering over the leaves. Clemson and Penn State water at the base, because wet foliage invites disease.
• Composting plants with downy mildew. Penn State says to discard them.

We found no Texas source with basil planting dates. Texas A&M’s statewide bulletin, Growing Herbs in Texas (2009), gives none, so the dates in the table above are counted from NOAA freeze records by Minnesota’s rule.

Questions

When can I plant basil outside?

Minnesota says after the danger of spring frost has passed. The table on this page gives your zone’s median last spring freeze and the later date it falls before in nine years of ten. Penn State and Clemson also wait for warm nights before setting plants out.

Why are my basil leaves turning yellow?

It may be downy mildew. UF/IFAS says its yellowing resembles a nutrient deficiency, and the tell-tale sign is spores on the undersides of the leaves, best seen early in the morning. Minnesota says it can kill whole plants.

Should I pinch off basil flowers?

For eating, yes. Minnesota says basil left to flower becomes woody, yields less and turns more bitter, and Illinois pinches out flower buds as soon as they form. Clemson says purple- or pink-flowered cultivars may be left to flower when grown as ornamentals.

Can I keep basil over winter?

Not outdoors where it freezes; Clemson says the first fall frost kills it. Clemson digs and pots plants before that frost for a sunny window, and Illinois sows fresh pots for the windowsill. Minnesota says even indoor plants will flower and die eventually.

How do I grow basil in Florida?

UF/IFAS says to plant it from seed in early spring or fall, in sun with a bit of afternoon shade, and to protect it on cold nights. UF/IFAS Pinellas County sows seed every few weeks for a steady supply, and UF/IFAS Duval County points to ‘Amazel’, a downy mildew resistant basil developed at UF.

Sources

Freeze dates on this page are NOAA 1991–2020 Climate Normals, for every station the ZIP codes in each zone cite. Zones are the USDA Plant Hardiness Zone Map, 2023. The planting rules are named beside the table. Growing advice is quoted from the extension publications below, each written for its own area.

• University of Minnesota Extension, Growing basil in home gardens , by Marissa Schuh and Shirley Mah Kooyman (Reviewed 2026). Written for: Minnesota (USDA zones 3a–5a).
• Penn State Extension, Herb Garden Plants: Basil , by Silloo Kapadia (Updated April 22, 2026). Written for: Pennsylvania (USDA zones 5b–8a).
• University of Illinois Extension, Herb Gardening: Basil . Written for: Illinois (USDA zones 5a–7a).
• Clemson Cooperative Extension, Home & Garden Information Center, Basil (HGIC 1327) , by Joey Williamson (Updated May 1, 2019). Written for: South Carolina (USDA zones 8a–9b).
• UF/IFAS Gardening Solutions, Basil (Accessed October 2026). Written for: Florida (USDA zones 8b–11b).
• UF/IFAS Extension Pinellas County, Try Growing Herbs (February 13, 2009; accessed October 2026). Written for: Pinellas County, Florida (USDA zones 10a–10b).
• UF/IFAS Extension Duval County, Grow the Right Herbs in the Right Places (April 24, 2025; accessed October 2026). Written for: Duval County, Florida (USDA zones 9a–9b).
• Texas A&M AgriLife Extension Service, Growing Herbs in Texas (E-561) , by Joseph G. Masabni (April 2009). Written for: Texas (USDA zones 6b–10b).
• Texas A&M AgriLife Extension, Aggie Horticulture, The Crops of Texas: Herbs and Spices (commercial production) . Written for: Texas commercial growers (USDA zones 6b–10b).

How we write our guides

Published October 23, 2026