The Proper Guide to Sowing and Thinning Vegetable Seedlings
A properly prepared seed bed is essential if maximum germination and growth are to be obtained. Seeds and seedlings need four things: moisture, warmth, air and, after germination, light.
The majority of seeds are small and need a line crumbly bed which should be prepared well in advance of sowing time. If seeds are sown in lumpy soil, they may lie in a pocket of air and when the tiny roots emerge, these will soon dry out.
Never make the seed bed when the soil clings heavily to your boots and tools. Particularly where the land is heavy, it should be turned over and left rough in winter. After frosts, it will break down and produce the tilth which is almost impossible to secure even by much labor.
Very heavy ground can be improved by the addition of sharp sand which will provide aeration, while finely ground peat will keep heavy soil open and prevent it drying out rapidly and cracking, which sometimes occurs on heavy land, to provide a suitable medium for growth.
Although dryness will not spoil germination before the process starts, once the seed coat opens, the young growth will soon die if the soil becomes dry. There are also seed-borne diseases which hinder germination, and insect pests and other hazards.
This underlines the necessity of sowing seed in really good soil, containing humus matter which encourages even germination and a plentiful root system. Discourage soil-borne diseases by practicing crop rotation.
Very shallow sowing is successful only if there is sufficient surface moisture present, from frequent showers, or irrigation. Deep sowing will only give good results if the weather remains dry enough to keep the surface soil open.
The rule should be therefore, to sow rather more deeply on light, easily drained ground and more shallowly on soil which is heavy and holds moisture for a long period. For most crops, one should aim at having a seed bed which is firm at the base and fairly loose at the top.
There are various ways of sowing seeds, the most usual being to draw out drills and then to sprinkle seed along them. Some gardeners mix very fine seed with sand, powdered peat or dry soil so as not to sow too thickly. Alternatively, a little lime may be added to the seed so that it will be easier to see where it falls into the drill.
There are various seed distributors on the market, some having a number of holes like a pepper pot. It is usually possible to adjust a distributor to regulate the number and size of the holes. Seed shaken from the corner of the packet rarely falls out evenly.
Drills can be scratched into the soil with the point of a draw hoe or a stick. Flat-shaped drills are usually made for peas and beans, especially if sowing double rows. Care is needed to ensure that the base of such drills is level, so that the seed does not become covered with varying depths of soil.
It is certainly wasteful to sow seed too thickly and then spend time thinning out. Apart from this, the scent that carrots and onions give off when handled, attracts carrot and onion flies. There is less trouble from these pests if thinning out is avoided.
Once the seed is sown a covering of fine soil should be given. Using the rake deeply may disturb the newly sown seeds. Afterwards firm the soil, which can be done with the head of the rake, to help the tiny roots to gain a hold.
A further very light raking of the surface soil will ensure that moisture seeps through evenly and does not settle along the drills. Should there be a prolonged spell of dry weather during which it is essential to sow the seeds, encourage germination by watering the opened drills generously before sowing the seeds.
Runner beans and peas can be soaked for a few hours before sowing but this is not always satisfactory as some seeds may rot before growth starts. Another method some gardeners adopt is to place carrot seeds between layers of damp cloth or muslin.
After a few days the germination process begins and the seeds can be sown in moist soil in the usual way. This does require care since wet seeds usually cling together and are difficult to separate.
Many early sown seeds, including peas and beans, may be attacked by a soil fungus which disrupts growth. This pre-emergence damping off can be prevented by dusting the seeds with a fungicidal powder available from garden stores or the internet.
Pelleted seeds enable you to sow them individually at the required distances apart. A drawback is that since the coating disintegrates slowly in dry soil, it is essential for the soil to be moist so that the material breaks up quickly and there is no delay in germination. Some pellets are made to split into two halves, leaving the seed free. Expensive F, hybrid seeds may be sold in pelleted form.
It is sometimes an advantage to sow vegetable seeds in containers and there are four main types to choose from. The seed box is particularly useful where a lot of seeds are to be sown and where they are expected to germinate freely.
The standard seed boxes, measuring 20 cm x 36 cm x 6 cm (8 x 14½ x 2½ins) deep, are a convenient size and can be placed closely together thus economizing in space. Wooden seed boxes have a comparatively limited life while plastic trays last longer and are easier to clean and sterilize.
The square earthenware seed pan is a useful container, although seldom used today. It is convenient where large quantities of slow germinating seed is being sown. Where a seed box would be too large, the 13-15 cm (5-6ins) round seed pan is a good receptacle for small quantities of seeds. The 13 cm (5ins) pot is not quite so good as the 13 cm (5ins) pan, since it is deeper than is necessary.
Pots and pans smaller than 13 cm (5ins) in diameter dry out rather quickly and are less suitable. Having chosen the container, the next thing is to provide drainage material. Crocks should be placed over drainage holes to prevent them clogging with soil, and it is a good plan to place a layer of fibrous peat or leaf mold or even rough loam, over the crocks before filling in with compost.
As far as the crocking is concerned, one large piece should be placed concave side down over the drainage hole, and two or three smaller crocks around it. If a deep container is used, several layers of crocks are advisable.
Charlie’s humic compost are very suitable for vegetable sowing although not essential, since a simple mixture of loam, a little peat or leaf mold and some sharp sand is sufficient for seeds to germinate evenly.
Fill a pot or seed box by lightly pressing the soil in with the fingers, slightly over-filling the container, and then striking it off level with a straight-edged, tapping the receptacle several times, before finally pressing level with a round or square presser or the base of an empty pot. This should leave the compost in the pot perfectly level and evenly firm, but not compacted.
If the compost is nicely moist at sowing time, little water will be needed until germination takes place. The compost must never dry out, but do not allow the surface to become caked from too frequent waterings. If it does, it may prevent the emerging seedlings from developing properly.