At this time of year, seeds should be sown under cover and in the warm, sunny windowsill, heated greenhouse. If growing seeds on a windowsill remember that temperatures plummet overnight so may benefit from being moved away.
You will need a shallow seed tray filled with seed compost. This is gritty soil and does not retain water. Seeds should be sprinkled on the soil with a light covering, preferably sieved.
Seeds come in bags of various quantities; however you should only sow what you think you will need. Last year I sowed 50 Brussel sprout seeds which all grew!.
A propagator provides an ideal environment for the emerging seeds but a plastic tray or bag will suffice.
Seeds require a light spray with water occasionally to keep the soil damp.
Young seedlings will grow towards the light so will need regular turning to keep them growing straight. Strong sunlight will burn young seedlings so netting the greenhouse may be required.
Once the seedlings have emerged and are large enough to be handled and have grown there first true leaves, they can be potted on. I use the end of a pencil to gently lift each seedling out of the soil, whilst holding the leaf. Do not hold the seedling by the stem as this will damage it. Use the pencil to make a hole in the soil in the individual pot and gently place the seedling into it. Cover the soil in around the seeding and water lightly.
Seedlings will continue to require a warm environment until night time temperatures increase.
Seedlings will require hardening off outside prior to planting out. The best way to do this is by bringing the young plants outside on warm sunny days and returning them at night.