Sweet Thai

Family: Lamiaceae Herb

Planting Schedule

Provide your location or planting zone to unlock dates and add Sweet Thai to a garden.

Sweet Thai basil opens with a vivid, licorice-cool fragrance and a bright, sweet-herbal flavor that lingers like fresh green tea on the palate.

Leaves are tender and glossy, with a gently serrated edge and a slender, upright habit that keeps foliage lush and aromatic through the season. Grow Sweet Thai for bold Thai-style garnishes, fragrant sauces, and quick pickling-style infusions where its distinctive sweetness and aromatic lift shine most.

Light: Full SunMaturity: 45 DaysHabit: Upright

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Sweet Thai Planting Dates by USDA Zone

Estimated US hardiness-zone windows for sow, transplant, and harvest. Enter a US ZIP above for exact local dates, or open a zone below.

Zone	Start Indoors	Sow / Transplant	Harvest
Zone 1a	Protected Environment Only
Zone 1b	May 4th	Jul 27th	Sep 10th – Aug 1st
Zone 2a	Apr 27th	Jul 20th	Sep 3rd – Aug 29th
Zone 2b	Apr 17th	Jul 10th	Aug 24th – Aug 25th
Zone 3a	Apr 17th	Jul 10th	Aug 24th – Sep 1st
Zone 3b	Apr 21st	Jul 14th	Aug 28th – Sep 21st
Zone 4a	Apr 17th	Jul 10th	Aug 24th – Sep 24th
Zone 4b	Apr 15th	Jul 8th	Aug 22nd – Sep 27th
Zone 5a	Apr 10th	Jul 3rd	Aug 17th – Sep 30th
Zone 5b	Apr 6th	Jun 29th	Aug 13th – Oct 5th
Zone 6a	Apr 3rd	Jun 26th	Aug 10th – Oct 10th
Zone 6b	Mar 28th	Jun 20th	Aug 4th – Oct 16th
Zone 7a	Mar 23rd	Jun 15th	Jul 30th – Oct 20th
Zone 7b	Mar 13th	Jun 5th	Jul 20th – Oct 28th
Zone 8a	Mar 4th	May 27th	Jul 11th – Nov 5th
Zone 8b	Feb 23rd	May 18th	Jul 2nd – Nov 12th
Zone 9a	Feb 6th	May 1st	Jun 15th – Nov 26th
Zone 9b	Jan 12th	Apr 6th	May 21st – Dec 9th
Zone 10a	—	Oct 1st	Nov 15th – Feb 28th
Zone 10b	—	Oct 1st	Nov 15th – Feb 28th
Zone 11a	—	Oct 1st	Nov 15th – Feb 28th
Zone 11b	—	Oct 1st	Nov 15th – Feb 28th
Zone 12a	—	Oct 1st	Nov 15th – Feb 28th
Zone 12b	—	Oct 1st	Nov 15th – Feb 28th
Zone 13a	—	Oct 1st	Nov 15th – Feb 28th
Zone 13b	—	Oct 1st	Nov 15th – Feb 28th

Crop Details

Trait	Value
Days to Maturity	45
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	60
Min Night Temp (°F)	50
Harden Off (days)	10

Culinary Notes

Chef's Note

Sweet Thai basil carries that cool licorice edge—don’t cook it down; add it off-heat or at the very last minute so the leaves stay tender and the aroma stays sharp. Its sweet herbal tone plays beautifully with salty-sour Thai staples like lime and fish sauce, making it feel like fresh green tea in food form.

Best Uses

Thai-style stir-fries where the basil hits at the end for fragrance
chopped-leaf garnish for curries and noodles (no simmering into dullness)
quick pickling-style infusions for a candy-sweet aromatic vinegar
fast-blended herb sauce where it stays glossy rather than muddy

Flavor Profile

anise-tinged licorice lift sweet, bright green-herbal flavor tender leaves that bruise into aromatic oils clean, cooling finish

Kitchen Pairings

lime garlic fish sauce chili coconut milk pork

Frequently Asked Questions

What pest or disease is most common on Ocimum basilicum (Thai basil), and how do I treat it?

Look out for downy mildew, which often shows as yellow patches on the top of leaves with fuzzy gray-purple growth underneath. Remove affected leaves immediately, improve airflow around plants, and water at the soil level early in the day so foliage dries fast; avoid wetting the leaf surface. If it keeps spreading, switch to a labeled fungicide for downy mildew on basil and repeat as directed.

How often should I water Sweet Thai (Ocimum basilicum) during peak growth?

During active leaf growth, keep the soil evenly moist but not soggy—water when the top 1 inch of soil feels dry. In warm weather in full sun, this may be about every 2–3 days, but always adjust to soil texture and pot size. Consistent moisture supports tender leaves, while alternating dry/wet can trigger leaf drop and make disease more likely.

How can I tell when Sweet Thai (Ocimum basilicum) is ready to harvest?

Harvest when plants reach about 6–8 inches tall and have multiple sets of fully formed leaves, usually around 40–50 days after sowing. Pick by snipping the top 2–4 inches (above a leaf pair) to encourage branching; avoid stripping all leaves at once. The best flavor comes from fresh, young leaves before the plant starts putting up heavy flowering stems.