Sweet Italian basil (Ocimum basilicum) is a fragrant, decorative annual herb ideal for Italian dishes and homemade pesto. Start plants in pots or a greenhouse for best results, using well-drained soil and plenty of sun. Prune above the second leaf pair to encourage branching and pinch out the centre shoot after six weeks to delay flowering. Harvest regularly through summer, and pick before any expected frost as cold will damage the plants; mature height about 12 inches (30cm).