Growing plants from seed is one of the most satisfying elements of gardening and yet many people are scared to give it a go, or give up too quickly after disappointing initial results. There are some fundamental rules which must be followed, but if you stick to them success is almost guaranteed.
Seed must be fresh; buy just before you sow and don’t use old seed that has been hanging around for years! Always use a specific seed sowing compost, never use potting compost which is too high in nutrients which can inhibit germination. Again, the compost should be fresh, or at least stored in a dry position; heavy wet old compost always gives poor results.
Use new, or thoroughly washed plastic seed trays (wooden trays are difficult to sterilize completely) . Fill the seed trays half full with compost and then level and firm LIGHTLY! with a flat object to produce an even surface. A riddle can be used to sieve the compost, producing a really fine seed bed.
The most common mistake when sowing seed is to sow too thickly; the result is overcrowding which leads to weak leggy seedlings and “damping off”, a disease which can spread like lightening through the whole tray. Small seed is the most difficult to sow and some seeds are like dust! Begonia semperflorens (Bedding begonia) is one of the smallest at 70,000seeds per gram, followed by Lobelia at 25,000 seeds per gram. Tap the packet very gently, at the same time move it over the surface of the compost so that it does not end up all in one spot. The second most common mistake is to cover with too much compost. In fact vermiculite (a lighweight volcanic particle) is much better than compost for covering as it doesn’t form a “cap” which seedlings can struggle to break through, and it also allows some light to reach the seed which is essential for some seeds. Having sown your seed, fill a fine (but not too fine!) riddle with vermiculite and gently tap the riddle over the seed tray. As soon as the seeds have disappeared from sight STOP! Water the seed tray GENTLY using a can with a fine rose attachment,taking care not to flood or puddle the surface and place in a suitable temperature (check back of seed packet). Very tiny seeds e.g. Begonias are best left uncovered but misting with water and/or covering with a pane of glass to prevent dehydration will be required. As soon as seedlings are large enough to handle they can then be pricked out into trays or pots to grow on.
