Fill a seed tray – almost to the top – with a moist seed and potting compost, and then thinly sow your basil seeds over the surface. Give them a light covering of compost and gently water in before transferring to a bright, warm room. Try not to allow the compost to dry out, but equally, do not over water. You can consider placing a plastic cover over the top of the seed tray to help maintain moisture and humidity, but this must be removed as soon as the new seedlings emerge to prevent fungal infection.
Once the seedlings have emerged through the compost keep them in a light position but out of direct sunlight. Once the second set of ‘true’ leaves have fully formed, transplant each seedling into 3 inch pots allowing no more than four plants per pot. After a couple of weeks - when the young plants have had time to establish - they can be gradually made accustom to outside conditions if that is to be their final position. Harden them off for a couple of weeks or so before planting outside, but only do so one the threat of frost is over. Choose a sunny, sheltered site for best results allowing 12 inches between each group of plants. The young tender leaves can be harvest any time – so long as the plant is big and strong enough – anytime from May until September.