Grow Thai Basil From Seed for an Abundant Harvest With Premium Taste!

If you're a fan of Thai cuisine, consider growing your own Thai basil. This herb has a unique flavor profile that sets it apart from other types of basil, with a spicy kick and hints of licorice or anise. Luckily, growing Thai basil from seed is a simple process that anyone can do. With just a few easy steps, you can have a steady supply of this delicious herb right at your fingertips.

Thai Basil (Ocimum basilicum) is a beautiful basil that produces large green leaves with dark purple stems and flowers. The distinct taste is different from Sweet Basil and Holy Basil. But like other basil plants, Thai Basil is easy to grow from seed. If you want a steady supply of Thai Basil, follow these easy steps to start growing from seed.

• Thai basil is a tender annual that does not tolerate cold temperatures. However, it will grow well in sunny locations with rich soil. 

• Thai basil seeds can be directly sown outdoors after the danger of frost is passed and the soil temperature is 70ºF.

• Choose a location that receives full sun, which means at least 6 to 8 hours of direct sunlight each day. 

• Plant Thai basil in soil that is nutrient-rich and loamy. The soil should be able to hold moisture and drain well.

Starting Thai Basil seeds indoors will give you the best germination rates. 

• Start Thai basil seeds indoors 6 to 8 weeks before the last spring frost.

• Place Thai basil seeds in seed starting trays or pots and plant 1/4” deep.

• A soil temperature of 70 to 85ºF is optimal for seed germination.

• Water by misting until the seeds start to sprout.

• Use a humidity dome or cover to keep the seeds moist and prevent them from drying out.

• Thai basil seeds should start sprouting in 5 to 14 days.

• Once the basil seedlings are growing, water from the bottom to avoid damping off.

• Thin out your seedlings once they have sprouted. Keep the largest and strongest to grow without competition. For more information, read about thinning seedlings.

Once the basil plants are several inches tall and have at least two true leaves, they will be ready for transplanting outside. 

Start by hardening off your Thai Basil seedlings so they will thrive in their new location. Hardening off is an important step that will ensure transplanting success. First, place the seedlings outside in a spot sheltered from intense heat or wind for 1 hour. Then increase the time by an hour each day. You can read more detailed information about how to harden off seedlings in our Planter’s Library. 

Make sure all danger of frost is passed before permanently moving your Thai Basil seedlings outdoors. Temperatures should be at least 70ºF. In the winter, plants will die off when temperatures drop below 40ºF.

Space the Thai Basil plants 12 to 18 inches apart. Giving them room to grow will allow for good air circulation, and their roots won’t be competing for nutrients.

When transplanting, make sure not to cover up the base of the seedling with soil. Plant only to the depth of which it was already growing.

Choose a location with full sun. At least 6 to 8 hours a day. These green leaves love to capture the light.

When planting Thai Basil in your garden, put it near plants with similar light and water requirements. If you have an herb garden, basil plants will fit right in next to your chamomile and oregano. Basil can also be added to a flower bed. It will help repel insects and can be used in flower arrangements.

A rich loamy soil is best for growing Thai Basil. Putting compost in the soil before transplanting will provide the necessary nutrients.

Basil prefers moist soil that drains well. Consistent watering of about 1 ½ inches a week should be sufficient. If growing basil in containers, more frequent watering may be necessary to prevent the roots from drying out. Be careful of overwatering. When roots remain too wet, they will become waterlogged, and the plant will turn yellow and eventually die.

Like other herbs, Thai Basil doesn’t need much fertilizer, but it does benefit from nitrogen for leaf growth. Adding organic matter, such as compost, to your garden beds before transplanting can help supplement the additional nutrients your plants need as they grow. If fertilizer is necessary, use a balanced fertilizer every 3 to 6 weeks at half strength. 

Basil makes a great companion plant because it naturally repels so many pests. 

For vigorous, healthy plants, keep weeds out so the Thai Basil doesn't have to compete for nutrients. 

Keeping the soil moist but not too wet will prevent root rot.