How to grow Basil
Updated October 2026
Basil is a fast, warm season herb in the mint family, grown for its fragrant leaves for pesto, tomatoes and Thai cooking. It hates cold, so it goes out only once nights stay above 50°F (10°C), and it keeps producing for months if you pinch it often and remove the flowers. Downy mildew has become the big problem in humid summers, so resistant varieties are worth seeking out.
📖 Our full guide: How to Grow Basil
Where to plant
Give basil full sun, or at least six hours, in rich, well drained soil with compost or composted bark mixed in. Clemson suggests a pH of 6 to 6.5. Wait to plant out until days are consistently in the 70s °F and nights stay above 50°F (10°C), as cold checks basil badly.
Timing follows the heat. In South Florida, basil grows best from late summer through the mild winter and early spring, and in Central and North Florida and the Gulf South it is planted in spring and again in late summer. In Texas and the desert, sow in early spring, and in the desert again in September, avoiding the hottest months. In California, sow from March to July. Across the North, the Midwest, the Mountain West and the Pacific Northwest, plant out in May or June after the last frost. In Hawaii, basil grows all year.
Choosing a variety
| Type | Examples | Notes |
|---|---|---|
| Sweet basil for pesto | Genovese, Serata | Large leaves; Genovese can grow 3 to 4 feet tall |
| Downy mildew resistant | Prospera, Amazel, Rutgers Devotion DMR, Rutgers Obsession DMR, Rutgers Passion DMR, Rutgers Thunderstruck DMR | The best choice in humid areas; resistance is not total immunity |
| Fusarium wilt resistant | Nufar, Aroma 2, Newton, Elidia, Prospera | For gardens where basil has wilted and died before |
| Thai and anise basils | Siam Queen, Thai | Licorice scented, for Asian cooking |
| Ornamental and compact | Spicy Globe, Purple Ruffles, Dark Opal, Pesto Perpetuo | For pots and edging; Pesto Perpetuo rarely flowers |
How to plant
- Sow seed indoors 4 to 6 weeks before your planting out date, about a quarter of an inch (6 mm) deep. Seedlings appear in 5 to 10 days at about 70°F (21°C).
- When seedlings have two pairs of true leaves, move them into small pots of their own for faster growth.
- Harden them off and plant out once nights stay above 50°F. You can also sow directly in warm soil.
- Space plants about 10 to 12 inches (25 to 30 cm) apart for small types and up to 2 feet (60 cm) for large Genovese plants, so air moves between them.
- If a late frost threatens, cover plants overnight with pine straw or an upturned pot or bucket.
Watering and feeding
Basil needs well drained soil but a fairly constant supply of moisture. Water at the base with a soaker hose, drip line or watering can, not over the leaves, since wet foliage invites disease. A 3 inch (8 cm) mulch of pine needles or shredded leaves keeps the soil moist and the leaves clean.
Do not overfeed. Clemson notes rapid, lush growth reduces the flavor of the leaves. Dig in compost before planting and give a light side dressing about two months later only if growth slows and the leaves turn pale.
Pruning and care through the year
- Pinch out the growing tips regularly, just above a pair of leaves, to make the plant bushy.
- Pinch off flower buds as soon as they appear for the best flavor. Let a few plants flower late in the season if you want to feed bees or save seed.
- To save seed true to type, keep different varieties at least 150 feet (45 m) apart. Do not save seed from plants that had Fusarium wilt.
- Before the first fall frost, harvest heavily, or dig a plant, pot it up and keep it in a sunny window.
Harvesting
Start picking once plants are about 6 inches tall, pinching off the tips of branches with one or two pairs of leaves, and always leave enough foliage for the plant to keep growing. Pick in dry weather, as cut stems are open to gray mold for a day or two until they heal.
Fresh basil does not keep long, even in the fridge. Dry it at under 125°F (52°C) or hang small bunches upside down in a warm, airy room, then store the crumbled leaves airtight for up to a year.
Growing in pots
Basil grows well in a pot at least 6 inches (15 cm) wide in a sunny spot, and compact types such as Spicy Globe suit small containers. Water pots more often than beds, but never leave them standing in water.
Companion planting
Basil is a natural partner for summer fruiting crops that share its heat and its kitchen uses.
Good companions
- Tomato Same planting time, sun and water needs; basil flowers draw pollinators and predators.
- Bell Pepper Peppers enjoy the same warm, sunny bed.
- Oregano Another sun loving herb for the same bed edge.
- Bell Pepper
Keep apart
Avoid planting these close to basil.
- Rue Rue prefers dry, lean soil and is often said to stunt basil.
- Sage Sage likes drier conditions than basil, so they are hard to water together.
Pests and diseases
In humid summers, downy mildew is the main threat. Good spacing and dry leaves prevent most other diseases.
Pests to watch for
- Aphids Clusters of small soft insects on tips and under leaves.
- Whitefly Tiny white insects that fly up from the undersides of leaves.
Diseases to watch for
- Downy mildew Yellowing between the main veins, then brown spots, with purplish gray fuzz under the leaves. Remove affected plants and grow resistant varieties.
- Fusarium wilt Plants 6 to 12 inches tall that stunt, brown at the tips and suddenly wilt. Remove them and plant resistant varieties elsewhere.
- Botrytis Gray mold spreading down from cut stems after picking in wet weather.
- Leaf spot Brown or black spots on leaves; water at the base.
Common questions
Why is my basil turning yellow with black spots?
In humid summers, the most likely cause is basil downy mildew: yellowing limited by the leaf veins, then brown spots, with purplish gray fuzz under the leaf. Remove affected plants, water at the base, space plants for air flow, and choose resistant varieties next time.
Should I cut the flowers off basil?
Yes, for the best leaves. Pinch flower buds as soon as they appear, since flavor and leaf growth decline once the plant flowers. Leave a few to flower late in the season if you want to feed bees or save seed.
When can I plant basil outside?
Once days are consistently in the 70s °F and nights stay above 50°F. In the North that usually means late May or June; in Florida and the Gulf South, plant in spring and again in late summer.
How do I harvest basil without killing it?
Pinch off the tips of branches just above a pair of leaves and never strip the plant bare. Regular picking makes it bushier. Pick in dry weather, as fresh cuts are prone to gray mold for a day or two.
Can I grow basil indoors over winter?
Yes. Before the first frost, dig a healthy plant, pot it up and keep it in your sunniest window, watering regularly without letting it stand in water. Fresh sowings in pots also work.
Why did my basil suddenly wilt and die?
If the soil is moist, Fusarium wilt is likely, especially in plants 6 to 12 inches tall with browned tips. The fungus lives in soil for years, so grow resistant varieties in a new spot. In the Southeast, bacterial wilt from tomato beds can also kill basil.
Sources we checked: Clemson HGIC: Basil; Rutgers: Four new Rutgers sweet basil varieties available to home gardeners; UT Gardens: Disease-resistant basil and downy mildew.
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