I actually started two trays of basil yesterday - a sweet summertime Genovese and a hardier Siam Queen. They will both germinate nicely on the heated shelves and will thrive under grow lights that stay on 14 hours each day. When we transplant them, they will take up space on heated tables in the greenhouse for a couple of weeks. Then we will bring them to the farmers' markets and admonish our customers not to buy them. They will be hideously expensive and probably will not thrive. But people will buy them anyway and some will have very goo luck with them - especially if they are potted up into larger containers and put into another greenhouse or solarium. I think it is better to wait til May when the soil is nice and warm to put it in the ground, but we will have it on our market table much sooner than that.
There are many kinds of basil and some tolerate cooler temperatures better than others. The favorite sweet basils, like the Italian Genovese, are the most tender. But the spicier Thai and Cinnamon basils do better in early spring and late fall. Two varieties that are not considered culinary - African Blue Basil and Holy Basil (Tulsi) - are perennial in our climate, though they will not survive a hard freeze. Both can be grown in large pots and brought inside during the coldest part of the winter. The African Blue Basil is a sterile hybrid that flowers continually but does not set seed. Bees and hummingbirds love it and it has a terrific sweet basil scent. Some people do use it in cooking, though its flavor is a little too sharp for eating fresh.
An anecdote: A couple of years ago I got a couple trays of basil ready for the farmers' market early in March. I left the house a bit before sun up with my basil and the first, ultra early tomato seedlings and a load of spring peas, greens, artichoke plants and other things and headed up the road. As the morning light appeared, I noticed it was very white out and when I got within five miles of the Aptos market at Cabrillo College I realized it was snowing. And I had basil and tomato seedlings. I made $87 dollars that day, and I will never forget it!