Seeds need warm, moist conditions for germination. They must have air too, or they might rot without sprouting. Seeds are sown outdoors only when the soil is warm and moist enough, but since conditions can be controlled indoors, seed sowing is possible all year round.Some seeds have built-in dormancy. This is usually a hard seedcoat, or chemical contained within, that prevents seeds germinating before the winter. Dormancy is usually broken by a period of exposure to cold, leaving the seeds ready to germinate right at the start of the growing season.Seed packets usually carry instructions about breaking dormancy, if this is a factor for a particular type of seed.
Sowing seeds outdoors
Vegetables, many flowers, trees and shrubs can be raised from seed sown outdoors. Dig the soil well in advance of sowing. Break down all lumps and rake the soil until it is fine. The soil should neither be too wet nor too dry.A useful test is to squeeze a handful of soil into a ball; if it does not fall apart at a touch, it is too wet; if it does not even form a ball, it is too dry. Rake in a dressing of general fertiliser at 70 grams per square metre, before sowing.Use a garden line to keep the row straight. Draw a little drill mark in the fine soil with a stick. Sow the seed at the depth and spacing suggested on the seed packet, cover lightly, and mark the row with a label. The packets also give suggestions on sowing dates. These usually cover between eight and ten weeks, to allow for British conditions.For Ireland, as a general rule, take the middle four weeks, leaning towards the first two in the south and east, and the second two in the midlands and north.When the young plants are large enough, thin them to their final spacing, or lift and transplant them to their final spacing. Thin by selecting strong plants at the required intervals and removing the rest.
Sowing seeds indoors
By sowing indoors, it is easier to provide warm, moist conditions, which makes it possible to germinate more difficult seeds. Seeds are sown in trays or pots of seed compost.Make sure that the trays are clean, and use only good quality seed compost – for example, Shamrock Seed and Potting Compost, Bio Seed and Cutting Compost, Fison’s Levington Compost.Water the trays before sowing, but not too much or the seeds may rot. Sow the seeds evenly and thinly, and cover lightly with fine compost shaken from a sieve, or vermiculite. Cover the tray with a sheet of glass and a sheet of paper.Place in an appropriate temperature – a warm room, propagator or greenhouse for most types of seed, the hot press for the few that like a high temperature. Watch carefully for germination.Remove the paper when the first seedlings emerge, and the glass a few days later. When the seedlings are large enough to handle, which is after ten days, prick them out into trays of fresh compost, at 5 by 5 centimetres, or into small individual pots.Ease them gently from the compost, holding them by the seed leaves to avoid damage to the stem. Water lightly with a fine spray, after transferral.