Plant Basil – After Warm Nights

Plant basil after nights stay above 50°F. Set a transplant at the same depth it grew in the cell, or sow seed a quarter inch deep.

Plant after nights stay above 50°F

Wait until nights stay above 50°F. Cold air and cold soil blacken the leaves and stall the plant. [1] Genovese basil is a tender annual. A late frost will kill a set-out plant overnight. Direct-sow after frost, or set a hardened transplant at the same depth it grew in the pot. [2] Sun and even moisture for the genus are on How to Grow Basil.

How to plant basil

Harden seedlings, then set them out on a warm day with room to breathe.

1. Wait until nights stay above 50°F. Cover the bed if a late frost is still on the forecast.
2. Set the transplant at the same depth it grew in the cell. Do not bury the stem. [3]
3. Space plants about 12 to 18 inches apart so air moves through the row. A compact Greek mound can sit a little closer than a tall pesto plant.
4. Water at the base after planting. Mulch once the soil has warmed, and keep the foliage dry.

Start seed indoors four to eight weeks before you set plants out

Sow a quarter inch deep in a warm, bright place. Seedlings that stretch in a dim window do not transplant well.

1. Sow four to eight weeks before your last frost. Cover the seed about a quarter inch. Keep the mix near 70°F. Seedlings usually show in five to ten days. [4]
2. Give bright light as soon as they sprout so the stems stay short.
3. Pot on after two sets of true leaves. Harden them outside for a week of warm days before they go in the ground.
4. Do not start African Blue from a seed packet. That hybrid is sterile — buy a cutting on Types of Basil.

What fails at planting

Setting plants out before nights stay above 50°F is the usual reason leaves blacken. Sowing seed too deep, or crowding the row, is the next. Wait for heat, cover the seed lightly, and give each plant air.

If the leaves blacken after planting, the nights were too cold — wait for warmer weather on the next round.