Advice
Sowing seeds indoors
Seeds sown indoors allow earlier flowering and cropping. The protected environment is also easy to manipulate for specific requirements.
Containers
Many
containers are available. Small seeds are generally sown in
a shallow tray and pricked out into larger pots. Slightly
larger seeds can be sown into individual modules if space
allows, limiting transplant shock. Large seeds can be sown
individually into 9cm (3.5in) pots. Old containers should
be thoroughly cleaned before use. 
Compost
Use a standard soil-based or soil-less seed composts for indoor sowings. These are finely milled and contain few nutrients, which could otherwise damage seedlings.
Method
Many
seeds require specific sowing treatments, such as light-exclusion
and scarification (scratching or nicking the seed coat), so
check seed packets for specific instructions. Fill the container
with compost, level, firm gently and water well. Sow seeds
thinly. Very small seeds can be mixed with fine sand before
sowing to obtain more even distribution. Sift a fine layer
of compost or vermiculite over the seeds. Label, lightly water
again and either cover with clear polythene and maintain a
temperature of 18ēC or place in a heated propagator.
Aftercare
Check
daily for emergence. Once seedlings emerge increase ventilation
and remove covers. Keep the compost just moist and, unless
sown individually, prick out seedlings at the first true leaf
stage. Gradually harden-off plants before placing them outside.
Further information
Conservation and Environment Leaflets
Energy conservation in greenhouses