Sowing Seeds in the Vegetable Plot
Sowing pelleted seeds
The soil for sowing pelleted seeds, either in a seed bed or in their permanent positions, must be kept moist without becoming sticky. If the ground dries out after sowing, the protective covering will not break up to allow the seed to germinate. If the ground is too wet, the coating will become treacly and stifle the seed.
Although pelleted seeds reduce the work of thinning, it would be unwise to take the risk of sowing single seeds at final thinning distances. Instead, sow two pellets in each station and remove surplus seedlings later, if necessary. Keep the soil moist by sprinkling until the seeds germinate.
Sowing in a seed bed
Leeks and most members of the cabbage family (brassicas) are best raised in a seed bed and transplanted to their permanent positions. The plants tend to be ‘leggy’ if sown where they are to grow.
Relate the size of the bed to the size of your vegetable plot and the family taste for brassicas.
As a guide, nine rows, each containing 30 plants, can be raised in a bed measuring 5 x 5ft (1.5 x 1.5m).
The vegetables in such a bed might comprise: two rows of leeks, and one row each of summer cabbages, autumn cabbages, savoys, Brussels sprouts, cauliflowers, broccoli and either sprouting broccoli or kale. This selection would provide greenstuff for most of the year.
Choose a piece of fertile ground and prepare the bed as for growing from seeds in the open — that is, digging during the autumn or winter, treading the ground when the soil is suitably dry in spring, and raking to a fine tilth.
In such a small area there is no need to use a line and hoe to make the drills. Instead, form the drills on light soils by pressing a rake handle about z in. (12 mm) into the surface. On heavy soils, use the rake handle as a guide and scratch the drill with a draw hoe.
Space the rows 6in (150 mm) apart, labelling each row as you go. This is particularly important in a seed bed because, when young, the various brassicas look similar.
Birds may be troublesome, pecking out the brassica seedlings as they emerge, so cover the bed with netting stretched over pegs.
Sowing under cloches
Some crops can be harvested earlier if they are given a start under cloches. Sowing times can be advanced by two or three weeks for vegetables such as carrots, French beans and lettuces.
Prepare the ground as for sowing in the open and place the cloches in position two weeks before sowing to warm up the soil.
Distances between rows will be governed by the height and width of the cloches. As the seedlings grow they will need headroom, so do not sow too near the edges.
Surface soil dries quickly under cloches, though usually there should be no difficulty if it was sufficiently moist at sowing time. During hot weather it may be necessary to water the soil before the seedlings appear.
During damp weather scatter pellets to control slugs.
Causes of failure
The complete or partial failure of a sowing is rarely due to the quality of the seed. If the seeds do not come up, you probably have time to re-sow, but first make sure that the crop has failed.
There are several common reasons for failure, and these may be identified if the seeds are large enough to be dug up and examined.
Soil too cold
The seed will be soft and decaying, with no sign of a shoot. This occurs in hardy crops sown too early in spring, and in tender crops, such as marrows, sown too early in April or May.
Delay first sowings of hardy crops until growth is evident in weeds and overwintered crops, and the soil feels warm to the touch after the sun has been on it.
Take local advice and do not be misled by sowing dates based on latitude. Spring in parts of East Anglia, for example, is often colder than further north.
Soil too dry The seed will be hard and appear much as it came out of the packet. In dry weather always soak the ground before sowing, and water at three-day intervals until seedlings emerge.
Seeds are liable to attack by spores of a soil-borne fungus, and in this case will rot and may be hard to find. This is more common in heavy soils than in light ones.
Before sowing, treat the seeds with a fungicidal dressing, obtainable from garden shops. Some, such as Murphy’s Combined Seed Dressing, also contain insecticides.
Peas and beans are particularly susceptible to these rotting-off troubles, butcan be greatly improved by shaking the seeds with fungicide in the packet. Be careful not to inhale the dust.
Occasionally, slugs may clear seedlings as they emerge. Sprinkle slug pellets over the bed immediately after sowing.
Peas sown under cloches in autumn or early spring are the most likely target of mice. Set traps under the cloches, or use bait obtainable from garden shops.
It may seem a paradox of gardening that seeds must be sown thickly enough to ensure a full row, then thinned out to give the plants room to mature. Thinning, however, is vital, otherwise seedlings become weak and spindly as they compete with each other for food and light.
Thin in three stages, starting as soon as the seedlings are large enough to handle, first to 1in (25 mm) apart, then to 2in (50 mm) and finally to the distance recommended for each vegetable.
Pelleted seeds, sown in pairs at their final spacings, only need thinning to a single seedling at each station.
Thin when the soil is damp to reduce root disturbance to the plants that are left. Put thinnings on the compost heap as they may attract pests if left between the rows — especially in the case of carrot thinnings.
At the second thinning, some of the plants removed — such as carrots, turnips and beet — may be used in the kitchen.
At the third thinning, check that only a single plant is left at each station. Sometimes a second plant may be missed, and this will be more difficult to remove later.
Plants in the seed bed need to be thinned only once before transplanting.
Germination times – and age limits for seeds
To minimise risks at sowing time, use only fresh seeds. Every seed packet carries the year of packing and an assurance that the contents comply with legal standards of germination.
The use of fresh seeds is particularly important with parsnips, whose seeds have a notoriously poor germination.
Other seeds may be sown safely a year after purchase if they have been stored in a dry, cool place. Some, indeed, have a much longer life, as the table below shows.
To avoid disappointment and the need to re-sow, test a sample of old seeds indoors a few weeks before they are due to be sown.
Count 20 seeds and sow them in a small container of moist seed compost. Place the container in a plastic bag and leave in a warm place, such as an airing cupboard, for the number of days shown in the column of germination times below. If 16-18 seeds germinate, the rest are worth sowing in the garden.