Thai basil (bai horopa) is sweeter than its Mediterranean counterparts and sports dark purple stems with purple shading on the leaves. Also known as Asian basil, this aromatic herb thrives in soil with pH levels of 5.5 to 8 and reaches up to 24 inches in height with a 24-inch spread. Thai basil is favored in Thai, Vietnamese and Laotian cuisine, with whole or roughly torn leaves being added to stir frys, soups and stews.
Choose a location that offers full sunlight and well-draining, loose soil.
Plant seeds directly in the garden in late spring when the soil temperature reaches at least 60 degrees F.
Amend the planting location with equal amounts of organic compost and coarse sand to create well-draining, nutrient-rich soil. Spread sand and compost over the site and work it into the soil with a pitchfork and rake until it is thoroughly incorporated.
Sow seeds directly on top of the soil, allowing 12 to 18 inches between seeds, then lightly cover with 1/8 inch of soil.
Water sown seeds lightly to set. Keep soil moist during germination but not saturated.