Basil starts in grow box - basil growing guide

Basil is a warm-weather, fragrant herb that’s great for flavor and aroma. If you plant seeds or transplants after all danger of frost has passed and the soil is warm, it will create a large harvest within weeks. To maintain the strength of the basil, keep harvesting the leaves. While the process of growing herbs indoors is easy, basil only grows in the summer and only once the soil has warmed up, so plan accordingly.

Planting and Growing Information:

Basil will grow best in a location that receives 6 to 8 hours of full sun daily, but it can also perform well in partial sun. Soil should be moderately fertile and moist but well-draining. Ideally, the pH of the soil should ideally be in the range of 6.0 to 7.5 (slightly acidic to neutral). For better drainage, basil works best in containers or raised beds. If you’ll be cooking with these basil plants, plant in clean soil with no insecticides, and make sure to grow them far from driveways and busy streets so that exhaust will not settle on the plants.

Begin planting the seeds indoors 6 weeks before the last spring frost. To plant them outside, wait until the soil has warmed up to at least 50°F—preferably around 70°F to experience the best growth. Temperatures during nighttime shouldn’t drop below 50°F. Don’t rush basil because without heat, the plant won’t grow well.

Sow seeds no more than ¼ inch deep. Once seedlings emerge and have 2-3 pairs of true leaves, make sure to thin seedlings to one plant every 10 to 12 inches. Basil should grow to about 12 to 24 inches in height. For larger varieties, plant the seeds farther apart (about 16 to 24 inches).

Make sure that the soil is moist as basil plants like moisture. If you live in a hot area, use mulch around the plants (doing this will help hold in moisture and suppress weeds). During the dry periods of summer, liberally water the plants. After the seedlings have produced their first 6 leaves, prune to above the second set, which encourages the plants to start branding and results in more leaves for harvest. Every time a branch has 6 to 8 leaves, repeat pruning the branches back to their first set of leaves. After about 6 weeks, pinch the center shoot to prevent early flowering. If flowers do grow, simply cut them off.


Add compost soil, natural fertilizers, or a 5-10-5 fertilizer every 4 to 6 weeks for indoor plants; every 2 to 3 weeks for outdoor plants. For an easy homemade fertilizer, you may re-use coffee grounds, stale beer, tea (green or black tea), or mineral water. Be sure to not over-compost your plants and regularly remove old coffee grounds and tea leaves.


Be sure to harvest early in the morning when leaves are at their juiciest. To encourage growth throughout the summer, pick the leaves regularly. If cold weather is expected or if a sudden frost is impending, make sure to harvest your basil beforehand because the cold temperatures will destroy your plants. Begin picking the basil leaves as soon as the plants are 6 to 8 inches tall. Once temperatures hit 80°F, basil will really start leafing out. Pick the leaves to keep the plant going and store them for later use, even if you don’t need them. If you pick regularly, 12 basil plants can produce 4 to 6 cups of leaves per week.