Basil is one of the easiest herbs to grow, and one of the most productive if you harvest it the right way. It is a warm-season plant that loves heat and full sun and is damaged by cold well above freezing. This page covers when to plant, how to space it, how to pinch it so it stays bushy, and how to keep it from going to flower too soon.
Basil at a glance
| Type | Herb |
|---|---|
| Season | Warm-season |
| Sun | Full sun |
| Plant spacing | 12 in |
| Row spacing | 18 in |
| Per square foot | 1 |
| Seed depth | ¼ in |
| Days to maturity | 60–70 from seed |
| How to start | Indoors 6 weeks before last frost, or direct sow after |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant basil
Basil is very sensitive to cold: temperatures below about 50°F can blacken the leaves, and frost kills it. Start seeds indoors about 6 weeks before your last spring frost, or sow directly outdoors once the soil is warm and nights stay above 50°F, usually a week or two after the last frost.
Check your last frost with the frost dates by ZIP code tool. For a steady supply all summer, sow a few more seeds every 3 to 4 weeks.
How to plant basil
- Give it full sun. Six or more hours of direct sun gives the most flavorful leaves. In very hot climates, a little afternoon shade helps.
- Use well-drained soil. Basil does well in beds and in containers at least 8 inches wide, as long as water drains freely.
- Space for air. Use the spacing in the table above. Good airflow helps prevent downy mildew, the most serious basil disease.
- Grow it next to tomatoes and peppers. All three like the same warmth and water, so they share a bed easily.
Caring for basil
Keep the soil evenly moist but not soggy, and water at the base rather than over the leaves. Container basil dries out quickly in summer and may need water every day in hot weather.
Pinch early and often. Once plants are 6 to 8 inches tall, snip the top of each stem just above a pair of leaves. Two new shoots grow from that point, so the plant becomes bushy instead of tall. Pinch off flower spikes as they appear, because once basil flowers, leaf growth slows and the flavor changes. Basil needs little fertilizer; a little compost at planting is enough.
Companion plants
| Grow nearby | Tomatoes, peppers, lettuce |
|---|---|
| Keep apart | Rue and other herbs needing much drier soil |
Basil likes the same warmth and moisture as tomatoes and peppers. Let a few plants flower to feed bees. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Downy mildew | Yellowing between leaf veins, with gray to purple fuzz on the undersides | Remove and bin affected plants, space new ones for airflow and water early in the day at the base. Look for resistant varieties. See the yellow leaf identifier. |
| Cold damage | Leaves turn black or dark and limp after a cool night | Basil is hurt below about 50°F. Cover plants or bring containers in on cold nights, and wait for warm weather before planting. |
| Fusarium wilt | Plants wilt and stems show brown streaks even with moist soil | There is no cure. Remove the plants, grow basil in a new spot or fresh potting mix, and choose resistant varieties. |
| Slugs, aphids and Japanese beetles | Ragged holes, curled leaves or skeletonized leaves | Hand-pick slugs and beetles, spray aphids off with water. See the pest identifier. |
| Wilting | Drooping leaves in hot weather or soggy soil | Check the soil before watering: both dry and waterlogged soil cause wilting. The overwatering checker helps tell them apart. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Start picking once plants have 6 to 8 sets of leaves. Harvest by cutting stems just above a pair of leaves, the same way you pinch, so every harvest makes the plant bushier. Take no more than about a third of the plant at once, and harvest regularly; basil left unpicked goes to flower sooner.
Pick in the morning, when leaves are freshest. Store cut basil like flowers, with the stems in a glass of water on the counter, because the fridge turns the leaves black. Harvest everything before the first cold night of fall.
Plan your basil
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant basil plants?
Space basil plants 12 inches apart in rows 18 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant basil seeds?
Sow seeds ¼ inch deep.
How long do basil plants take to grow?
Most varieties are ready 60–70 days from seed. Check the seed packet, because early and late varieties differ.
How much water do basil plants need?
About 1 inch of water a week, from rain and watering combined. Keep the soil evenly moist but not soggy, and water at the base of the plant. Basil in containers may need watering every day in hot weather.
Why is my basil flowering?
Basil flowers when it is mature, stressed by heat or dry soil, or not harvested often enough. Pinch off the flower spikes and harvest regularly to keep the plant producing leaves.
How do I keep basil from getting tall and leggy?
Pinch the top of each stem above a pair of leaves once the plant is 6 to 8 inches tall, and give it full sun. Each pinch makes two new shoots, so the plant fills out.