Few things give as much pleasure as raising plants from seeds. In most cases this is also substantially less expensive than buying plants and makes available a much wider choice of varieties. Although some are much easier than others and there are varieties that will only come true if raised from cuttings or by some other vegetative means, a huge variety of plants can be readily raised in this way.
Of course a certain amount of care is needed. You cannot just throw seeds in any old how or at any time of the year and expect good results. A little trouble taken to understand and meet their needs, however, will be well rewarded and anyone can do it, even a complete beginner. There are no such things as green fingers or lack of them!
What is a seed
A seed is an incredible feat of packaging; a small plant in embryo form, complete with a food store and all protected by a tough outer skin. Kept dry it will remain dormant but, in most cases, stay alive (remain viable) for one to several years, particularly if stored under cool conditions. When exposed to a favourable combination of moisture and warmth it will usually start to take up water. This causes it to swell which, in turn, results in the skin bursting and allows the embryo plant to start into growth. This process is what is called germination.
Although a few seeds have specialised needs, the following are the basic requirements for success:
Once sown seeds must be kept moist at all times. Allowing them to dry out before watering again, particularly once they have started to germinate, is a sure recipe for failure. At the same time the soil or compost should never be waterlogged.
Seeds vary in the temperature range they prefer for germination. Kept below this they will either germinate very slowly or not at all and may even rot. Kept above they can often remain dormant. Despite these differing requirements, most will germinate very well at a comfortable room temperature, as long as the room is kept warm at night as well as in the day.
This needs to be well drained, well aerated and not too rich in fertiliser. For pots and seed trays a wide range of seed and general purpose composts are available. Garden soil is not suitable for this purpose and only fresh compost should be used. In the garden the soil should be thoroughly broken down to a fine ‘tilth’ and be moist but not too wet.
CORRECT SOWING DEPTH
A covering of soil or compost helps to keep seeds moist but small seeds with only a very small store of food cannot grow from any great depth and so are best sown at or near the soil surface.
LIGHT Next page
Most seeds don’t require light to actually germinate and are best covered so as to exclude most light until the first seedlings start to appear. A few, such as impatiens and many primulas, do need light and must be sown at or near the surface and not otherwise be covered after sowing.