For greenhouse cultivation: sow from February to March.
For outdoor cultivation: sow from March to April.
Sow seeds on the surface of a good, free-draining, damp, seed sowing mix and cover with a fine sprinkling of compost or vermiculite. Place seed trays in a propagator at a constant temperature of around 15-20C (59-68F) until after germination, which takes 7-14 days. When seedlings gain 2 true leaves, transplant into individual 7.5cm (3″) pots of compost and grow on at a minimum temperature of 15C (59F).
When growing in a heated glasshouse tomato plants may be transplanted at the end of May or when the first flowers are showing, if earlier. Allow 3 plants per growbag, or one per 25cm (10″) pot, or plant tomatoes directly into the greenhouse soil.
When growing tomatoes outdoors, wait until all risk of frost has passed before transplanting tomatoes. Gradually acclimatise them to outdoor conditions over 7 – 10 days before planting out from early June when tomato plants are 20cm (8″) tall. Choose a sheltered position in full sun on fertile, reliably moist, well drained soil, and transplant at a distance of 60cm (24″) apart. Drive a (5′) cane into the soil adjacent to each plant to support them as they grow, and tie each main stem to its support with soft garden twine.