Time to sow your tomato seeds

NIGEL COLBORN’S ESSENTIAL JOBS FOR YOUR GARDEN THIS WEEK

FROM this week onwards, you can sow tomato seeds in your greenhouse. You’ll need a guaranteed frost-free greenhouse and a heated propagator. Optimum soil temperature in the propagator should be 18c to 20c. Fill a small pot with sterile seed-sowing or general purpose potting compost. Gently firm the compost down, but don’t compress it too much.

Place individual seeds on the compost surface about 1 cm apart. Then shake a thin covering of sieved, sterile potting compost over the seeds. Water the pot(s) with extreme care.

With bottom heat in a propagator, your sown seeds should germinate within a few days. Keep them warm and away from draughts, and water when necessary with great care. The sown pots must be kept warm until they are ready to prick out.

When the seedlings are large enough to handle, prick them out and pot them individually into 7cm pots or cell trays. Grow your baby tomatoes in full light and warmth — ambient temperatures should not be allowed to slip below 15c.

When growing tomatoes, it’s important to know which type they are; bush or ‘determinate’ varieties cannot be trained as cordons.

If you plan to grow your tomatoes in a greenhouse, choose indeterminate varieties.

These can be developed as cordons or ‘vines’, by constantly removing side-shoots and growing the individual stems up canes or strings attached to the greenhouse roof.