When to sow your vegetable seeds
Outdoors, the growth rate of seeds and plants is largely dependent on the weather conditions prevailing at any given stage in their development. Indoors, fluctuations in temperature can be kept to the minimum, watering and humidity are within your control; you do not have to face the extremes of drought, rainstorms, frost and snow. This enables you to sow earlier and enjoy earlier cropping, thus extending the growing season to a larger proportion of the year. There are also some vegetables which can be sown and grown almost throughout the year, including, sprouting beans and mushrooms, so it is possible to obtain a continuous supply. Generally, however, for the majority of the crops the plant growth remains related to the seasons, in that seeds normally sown in spring outdoors are also started indoors in spring – but about four to six weeks earlier in the right conditions. You can continue harvesting crops well into autumn, as there is no fear of early frosts spoiling the vegetables.
To obtain the maximum amount of produce from your limited growing space you should practise the system of succession sowing, which provides usable amounts of vegetables continuously rather than a mass of plants all at the same time. Make small sowings at intervals of about two weeks, so that as one crop fully matures and is harvested, the next is just coming to the harvesting stage, and so on. Experience will soon tell you how many seeds to sow in one batch to meet your culinary require- ments. You do need a good supply of containers to do this, from seed trays to large-size pots, as you will have several sowings in different stages at one time.
Sowing the seeds
It is a common error to sow seeds too deeply in the. This delays the appearance of the above the soil surface after germination, and they have to waste energy in growing up towards the light which would be better spent in their development above ground. In the majority of cases, the seeds are sown just below the surface of the soil, about lA’m (5mm) deep; a few are sown at ‘/2in (1cm) deep. There are one or two notable exceptions to this rule, such as and runner beans which are covered with 2 in (5cm) depth of soil. Generally you can just scatter or place the seeds on the soil surface and cover them with a layer of potting mixture.
Saving your own seed for use in the next year’s growing season is rarely practical. A proportion of the crops has to be allowed to run to seed – acceptable in a large garden which is densely planted, but a waste of cropping potential in container gardening. A number of the recommended varieties are Fl hybrids, which are unsuitable for self-seeding in any conditions.
To prepare the containers for sowing, fill them with potting mixture and firm the surface lightly. It should be level and smooth, but not heavily compacted. Moisten the soil before sowing and be sparing with the application of water; the soil should be damp to encourage germination, but not wet. If the underlying soil is damp there is no need to water again when you have covered the seeds. If the soil dries out before the new growth shows above the surface, it is better to dampen it with a spray rather than a watering can, as a jet of water can disturb the germinating seeds which are just beginning to root in the soil.
Young plants need space to develop from the earliest stages, so there is no advantage to letting the seeds lie thickly in the soil. If you need a large crop, use more containers with fewer seeds in each. If the seeds are too small to be placed separately at suitably spaced distances from each other, sow them very thinly to save wastage and make it easier to thin out the seedlings as they grow. When the seeds are in place, simply sprinkle a top layer of potting mixture over them to the required depth.
Germinating seeds need warmth and moisture, but light is not essential. In fact, most should germinate in the dark, and a shady location will do no harm to those which can germinate in light. You can place the containers in a closet, or in a utility room or basement with no windows, provided that the temperature is high enough and evenly maintained. It the seed trays or pots must stand in the light, a simple solution is to cover them with a sheet of black plastic. You can cut pieces from an opaque plastic refuse bag and place them over the containers; there is no need to tie them on as this prevents ventilation.
The even warmth of central heating provides ideal conditions for germinating seeds, but it may have a drying effect so it is necessary to monitor the moisture content of the soil. If your home does not have central heating, keep the containers in the warmest place least exposed to currents of air and sudden temperature changes. Do not site them close to a gas fire or cooker, as the fumes are detrimental.
As soon as the seedlings show above the soil surface, remove the coverings and place the containers in the light.