Thai Sweet Basil

Basil

60d to harvest

Aromatic and intensely sweet from the first pinch—Thai Sweet Basil fills the garden with a fragrant, anise-citrus perfume and delivers tender leaves with a crisp, slightly succulent bite. The foliage is lush and upright, producing abundant, narrow leaves that hold their character for fresh use and are especially prized for bold, fragrant flavor in stir-fry style cooking and quick sauces. Grow Thai Sweet Basil for a steady harvest over the season, and enjoy its signature lift in every aromatic application.

Crop Dates

Growing note: In frost-free Zone 10a, grow this cool-season crop during the cooler dry season (October–February).

Milestone	Date
Start Indoors	—
Climate	Frost-Free Climate
Transplant / Sow Outdoors	Oct 1st
Harvest Begins	Nov 30th
Harvest Ends	Feb 28th

Crop Details

Trait	Value
Days to Maturity	60
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

Frequently Asked Questions

What pest or disease most often hits Ocimum basilicum (Thai sweet basil), and how do I stop it?

Watch for downy mildew and leaf-spot issues, especially in warm, humid weather with wet foliage. Improve airflow by thinning crowded plants and water at the soil line (not the leaves), then remove any heavily spotted leaves. If problems spread, apply a labeled fungicide for basil downy mildew/leaf-spot according to the product directions, and avoid harvesting or working plants when foliage is wet.

How often should I water Thai sweet basil during peak growth so it stays productive?

During the main growth phase, keep the root zone evenly moist but not soggy—water when the top 1 inch of soil feels dry. Expect roughly 1–2 deep waterings per week in typical summer conditions, increasing frequency during hot, windy spells. Consistent moisture prevents bitter leaves and helps basil keep pushing tender new growth.

How can I tell when Thai sweet basil is ready to harvest?

Harvest when plants are about 8–12 inches tall and have developed multiple sets of mature leaves, typically around 60 days from sowing (often sooner if conditions are ideal). Pick by snipping above a leaf pair to encourage branching, and start with frequent light harvests rather than stripping the plant once. Stop major harvesting when flowering begins, since leaf size and flavor shift as Ocimum basilicum transitions to bloom.