How to Sow Seed
Sowing operations vary considerably according to the type of seed, where it is sown and where it is to be grown.
Perhaps the simplest of all seed-sowing operations is the one which every child at some time or other carries out, that is, the sowing ofand . This seed is sown either in the open garden, on finely raked patches of , or in boxes of soil, or on pieces of flannel, and beyond keeping the soil or flannel moist, so that the seed germinates, no attention is given. It is even unnecessary to cover these seeds with soil; they are merely sown thickly, pressed down flat on to the soil surface, and kept moist by being covered with pieces of paper or mats.
From the fact that mustard and cress grows as it does on pieces of flannel with only water, it can be seen that seed, to germinate, requires only moisture and a certain degree of warmth. The process of germination is entirely mechanical. At first the seed is dry, and covered by a skin or shell. If moisture is given, the seed swells and the outer skin bursts. When this has occurred the seed wants, like a newly-born child, air, as well as food and warmth. That is why seed must be sown on soil which is porous and open in character, and into which air can easily penetrate
The first step inis to prepare the soil so that at least the top 2 or 3 in. is porous and open. It must also be broken very finely. Otherwise large clods of earth might cover fine seeds and the seedling’ would be unable to push their way up into the daylight.
Seeds are sown in the open in two ways, broad cast and in drills. Broadcast sowing merely means that the seeds are thrown as evenly as possible all over the surface of the soil. This is the method that amateurs generally adopt for sowing annual flowers in the mixed border.
The mistake which is most common is in sowing the seeds too thickly. It is not easy to sow fine seed so thinly that when it comes up,will not be overcrowded. In fact, it is impossible. However, if few seed is mixed with sand before sowing, it will distribute more evenly and less thickly. This method is often adopted with expensive seeds.
Another good practice in sowing a patch of flower seeds, where seed is scarce and the seedlings are expected to occupy considerable space-when they develop, is to divide up the patch to be sown (in imagination or reality) into a number of squares, and to sow seed in each square. If the squares are spaced so that one seedling growing in each square will be sufficient, the operation of thinning will be greatly simplified.
As an example: If a few seeds of a new Marigold are being sown, they can be sown 10 in. apart, using about three seeds on each station. As they germinate, the two weakest will be removed, and only the strongest seedlings left to grow on to maturity.
In the case of certain dwarf plants such as Virginian Stock, Scarlet Flax, Nemophila, and Phacelia campanulata, no thinning is necessary if the seeds are distributed as widely as possible when they are being sown. As in the case of sowing mustard, it is essential that each seed that falls on the ground should be in actual contact with moist soil, for the process of germination to begin. It is therefore advisable to throw a little sand or fine soil over the seed after sowing, or to rake the surface a little so that the seed automatically falls into the cracks of the soil, and then to complete the task by pressing the soil down with the back of the spade, or with a trowel or rake.
In dry weather always water the soil after sowing seed outdoors to give the seeds a start.
But with this reservation—if the soil is sticky clay, do not water heavily unless you have used only sand as a surface covering. Sticky soil may easily become caked over seeds and delay or prevent growth. Carrots frequently fail for this reason.
Sowing in Drills
A drill is actually a shallow V-shaped trench drawn along a straight line, using the edge of the rake, the point of a triangular hoe or some other similar pointed tool. In order to keep the rows straight, so that the hoe can be used between the seedlings easily, a line of string is usually stretched across the border, or plot, each end of the string being attached to a peg which is driven in to hold the string taut.
When seeds are sown on an allotment, or vegetable patch, each drill is drawn by the side of the string, and the string is then moved on 12, 15, or in., as desired, so that the next line of seeds is exactly parallel with the first.
In this type of sowing the seeds are, as a rule, scattered thinly along the drill. Here again, however, with expensive seed it is possible to economize by sowing a pinch of seed at regular intervals along the drill, in the places where each matured plant will be. For instance, an expensive new variety of carrot can be made to go a good deal farther if a pinch of seed is sown every 6 in. along the drill. As the seedlings germinate they will be reduced to one at each station, and later, if the carrots need more room, each alternate root will be pulled out for use in salad or soup, while the rest are allowed full room for development.
In the case of drills, the seed can either be lightly covered with a sprinkling of additional soil, or the rake can be used to cover them, raking always in the same direction as the drill. The back of the rake often makes a handier tool for this purpose than any other. As before, the seed-sowing operation should be completed by pressing down the soil over the seeds with the rake (held vertically).
Seeds Under Glass
Seeds under glass are sown (1) in the soil of the cold frame, (2) in seed boxes, usually 3 or 4 in. deep, and (3) in pots.
Seed boxes can be any depth according to the type of seed, but the majority of fine seeds are sown in boxes 3 or 4 in. deep, filled to within an inch of the top with old sandy soil. As a rule, the boxes used are rather badly fitting, therefore the surplus water freely escapes between the joints and there is no need to provide extra drainage holes. Should a box be selected that does not allow the free escape of water, drainage holes will be burnt or drilled in the bottom.
For ordinary seed sowing, a layer of dried leaves in the bottom of the box is usually the best material. It keeps the soil from washing away and also allows free drainage. The soil used can be any ordinary garden soil, to which plenty of sand has been added. It is lightly filled in, after sifting, so that the box is just level full, and then it is gently pressed down with a piece of flat board, so that the surface comes about an inch below the rim.
Shallow drills, for ease in sowing fine seed, can be made by pressing one edge of the piece of board into the surface. Costly seeds, sown sparingly along such shallow drills in the boxes go farther and need less transplanting than if the seed is sown thickly all over the surface. Cover the seed with fine dry soil, or sand.
It is always a mistake to cover seeds too thickly. Nature’s method of seed sowing is to scatter them on the soil surface, and let them fall into the cracks. The only case in which a rather heavier covering of soil is used is when seeds are sown in the open garden in the hottest weather. If they are lying too near the surface the seedlings are often killed by the dry conditions, even if germination takes place.
Seed boxes are best watered before the seed is sown. If they need watering afterwards, before the seedlings have appeared, it is best to do it by half immersing the box in a bath of tepid water. Care must always be taken not to wash fine seeds out of the boxes, pans, or pots in the process.
Seed Sowing in Pots
Where pots are used for seeds it is usual to provide crock drainage at the bottom of the pot, about a third of the distance up the pot, and to use a certain amount of decayed leaf soil with sand in the upper part of the pot. Seedlings are frequently grown on in the pot longer than they would be in seed boxes, and on leafy, or leaves, in the lower layer help to feed them. Otherwise sowing is the same. Large seeds are, of course, sown singly in pots, or in the soil of the boxes, being pressed in, 2 or 3 in. apart. The rule for seed sowing is to cover the seeds with twice their own depth of soil.
Alpine plants from Seed
Very rare alpines are often sown in shallow pans filled with extra fine sandy soil. Because they are so rare, and so fine, and may take a good time to germinate, the amateur must be especially careful over watering, so that the seeds are not washed out. A very useful practice in raising alpine seeds is to use double pans. The seeds are sown in one pan, which is plunged up to the rim in a larger pan containing similar sandy soil. When water is necessary the outer pan anly is watered and the moisture gradually finds its way into the inner pan. This prevents any possibility of washing seeds away. Alternatively the seeds can be sown in the outer rim and water given in the inside pan only. Such fine seeds are covered with sandy soil sifted through a fine gauze.
Seeds of Shrubs and Trees
Amateur gardeners do not always realize that they can raise many varieties of shrubs and trees from seed by gathering berries, such asberries. It is best to keep them for a time, and the usual way is to pack the berries into sand and leave them for anything from 6 to 12 months. At the end of this time (or when convenient) the seed and sand are sown together. The reason for this delay is that the outer covering of the berry has to rot away before the seeds are ready for sowing. In Nature, the berries might he on the ground surface for a considerable time before the seeds began to grow.
The most common trouble amongst seedlings is the disease known as “damping-off.” This is a form of decay which attacks particularly seedlings that are injured in transplanting. It is also found amongst seedlings where ventilation is insufficient, or where too much moisture is used. It is to prevent the appearance of this disease that a very sandy compost is always used under glass.
An added precaution is to sterilize the soil before it is used. A solution of 4 oz. of formaldehyde to a gallon of water, poured over the soil before use, will almost certainly prevent the appearance of damping-off.
Should seedlings appear to be slightly affected, the disease can be prevented from spreading by watering them with a solution of per-manganate of potash crystals, used at sufficient strength to make the water a pale rose colour.