From Seed to Seedling

 Plant mortality is highest at the seed to seedling stage. Every seed is really a structure that embodies and protects the baby plant or embryo, plus a certain amount of food to tide it over the early stages of germination and growth. The moment a seed is wakened from its suspended animation and begins to grow it becomes vulnerable, not only to insects, bird, and animal life, but to conditions present in its environment.

Although the hereditary characteristics of the plant are already fixed in the seed, health, vigor, and constitution are greatly affected by its germination and growth from seed to seedling. The more robust, thriving, and successful plants come from seeds that germinate quickly and grow without check. The gardener's task at sowing time is to establish those most conducive to ready germination.

The majority of actively growing plants contain about 90 per cent of their weight in water. Seeds contain only about 10 per cent of their weight in water. Moisture is therefore an essential to germination, to forward the necessary biochemical changes which can only go on in solution. The speed with which seeds germinate is greatly affected by the moisture content of the soil.

Sown in dry soil, in dry weather, they may lie dormant for many days. Each seed coat is providentially pierced with a tiny hole admitting moisture and oxygen. without oxygen seeds do not germinate, for the gas is necessary to the chemical reaction which liberate the energy for growth. Weed seeds, long buried in the soil, germinate when brought into aerated surfaces, to annoy and baffle the gardener, particularly when they are weeds he has rarely seen in his garden before.

The third essential for seed germination is warmth. Seeds sown in a moist soil at low temperatures are liable to rot. Seeds in themselves, while dormant, can withstand amazing variations in temperature. Dry seeds have been known to withstand the temperature of boiling water without injury, and a variety of seeds have been kept at a temperature of 300 to 450 degrees Fahrenheit of frost, or immersed in liquid air, without injury to their germination powers.

The rate of biochemical action involved in germination is, however, greatly accelerated when seeds are sown in correct heat. It is when the embryo begins to stir that it develops its greatest susceptibility, the susceptibility of the plant, to temperature. Seeds sown out of doors early in February or March often show little gain over those sown a fortnight or more later. Speed in germination is retarded, and in itself there is little advantage in sowing early.

Germination speed, not the sowing time or season, determines the maturity date. The better start the seed makes, the finer plant it may become. Sowing time is more suitably gauged by the weather than by the calendar or the gardening guide. Rising temperatures arrive later, and leave sooner; the nearer we get to the poles or to the heavens. The time to sow a specific type of seed is largely related to its ancestry and native place.

Runner beans hail from Mexico. In temperate zones, therefore, they must be sown late in spring, after the danger of frost is largely removed. In germinating flower, shrub, and tree seeds even greater consideration of the native habitat of plants must be given. Experiment and experience must guide the gardener in many instances. Therein lies much of the fascination of his craft.

The tilth of the in which they are sown largely affects the seeds' ability to absorb moisture. The finer the seed the more powder-like should the seedbed be. A seedbed should be dug and allowed to settle and consolidate at least thirty days before sowing. Winter weathering gives a surface soil that can be rapidly worked and raked into a smooth even bed.

Seeds sown in recently turned soil are apt to be washed down below germination depth along with the particles of soil as the earth settles. They must also face the competition of weeds brought to the surface by digging, and germinating alongside. The depth at which seeds are sow affects their access to oxygen as well as moisture. A sound rule is to sow at a depth twice their diameter.

Bigger seeds, like Pea and Beans, with hard, tough seed coats, can withstand more depth than fine soft-shelled seeds, like parsnips. Firming presses seeds into contact with the soil particles, but should not be overdone. The energy and force a seed has to use in seeking the light has much to do with its success in germination and emergence as a plant.

Fine soil sifted over seeds tends to cake and flake, and must be pushed back by the emerging first leaves. A sifting of coarse-grained sand is less taxing and results in a greater percentage of germination. Soil texture has a bearing on the pore space which influences a soil's moisture content and aeration. Better germination is possible at slightly greater depths in light sandy soils, and at a slightly less depths in clay, but the variations are only fractions of an inch.

The period of dormancy in seeds varies greatly. Some loose their viability, capacity to resume activity, quickly. Lotus seeds have been germinated which were known to be at least 150 years old, but under normal conditions the seeds of the Japanese willow, if not sown, perish within a week. Gardeners are often warned against planting parsnip seeds more than 18 months old.

A broad line can be drawn between the seeds that have soft seed coats and those which are hard shelled, the latter retaining their germinating powers for a greater period. For the part, new seeds germinate more readily and produce more vigorous and finer plants than old seeds. When seeds are sown indoors, under glass, or in greenhouses, temperature, moisture, and other factors are more strictly under our direct control.

As seeds need no food until they reach the baby plant stage, they can be germinated in moist sand, sphagnum moss, poor soil, or even peat, only, but a more satisfactory control on moisture and aeration in afforded by making a seed compost. As it is difficult to draw a line between the exhaustion of a seed's own food reserves and its subsequent dependence on its environment, it is also wise to make up seed composts sufficient rich and suitable for sustaining unbroken activity and growth.

The first stages of plant life are so vital to the future growth that it is surprising that the fundamental operation of preparing seed and seedling compost received little critical scientific attention until 1963. Thanks to the exhaustive experiments carried out by the Scottish Horticultural Institution this problem has been very practically solved for us.

The Scottish formula for seed compost gives a well-balanced compost of good texture for general seed sowing indoors https://yummytastefood.com/. The addition of phosphates in seed composts is invaluable since phosphorus is especially required for root and leaf growth in the seedling stages. A light dressing of the seedbed with superphosphate always pays dividends in sturdier seedlings, equipped with bigger leaves, and more actively foraging roots.