Early sowings can be undertaken under glass at approximately 20°C, in trays or pots filled with good quality seed compost. Surface sow thinly and water from the bottom of the pots by sitting them in a tray of water for a short time when necessary. When large enough to handle, grow on in small pots and gradually harden off before planting outside at 45cm intervals after frost. As the seeds are so small it may help to mix them with a little sand before sowing. This will help you keep track of where they are and also avoid overcrowding.