Another basil tip. The basil in a pot that you can buy at the supermarket is not a single plant but a cluster of about 20 seedlings. Choose one with lots and then plant them out in the tunnel house or a sheltered corner of the garden. Much cheaper than buying a pack of basil plants at the warehouse or garden centre.
When you are harvesting basil, as well as making pesto, freeze some leaves in very small plastic bags. They will last all year in the freezer. Just take one out, crumble it (while it is still crunchy) into pasta dishes. It keeps all the fragrance and flavour of fresh basil.