How to grow basil

Basil loves heat. Plant it once the weather is truly warm, pinch it often, and it will keep producing all summer.

Reviewed October 2026

Start indoors

4–8 weeks before planting out

Plant outside

When days stay in the 70s

Spacing

2 ft apart, rows 3 ft

Seed depth

1/4 in

When to plant

Basil is a warm-season plant. Clemson Extension recommends sowing indoors 4 to 6 weeks before planting out, and UNH Extension 6 to 8 weeks, so anywhere in that range works. Move plants outside when daytime temperatures are consistently in the 70s and nights stay above 50°F, which is usually about 2 weeks after your last frost. The planting planner gives you dates.

If a late cold snap threatens after planting, cover plants overnight with an upturned pot or bucket.

Sowing and spacing

• Sow seeds 1/4 inch deep. They germinate in 5 to 10 days at about 70°F.
• Choose a sunny spot. Basil prefers full sun but manages with about 6 hours a day.
• Space plants 2 feet apart, in rows 3 feet apart.

Pinch for bushy plants

Pinch out the growing tips regularly to make plants branch, and pinch off flower buds as soon as they appear for the best flavor. Harvest by picking leaves or pinching off stem tips with a pair or two of leaves, and always leave enough foliage for the plant to keep growing.

Preventing downy mildew

Downy mildew spreads fast in mild, humid summers and can wipe out a planting.

• Keep leaves dry: water at the base with drip lines or soaker hoses.
• Plant in full sun and space plants widely for good airflow.
• Grow resistant varieties such as 'Prospera', 'Rutgers Devotion' or 'Rutgers Obsession'.
• Remove infected plants and fallen leaves, and plant basil in a different spot each year.