The Content Of The Article:
- Different types of sorts
- The seed as energy storage
- The starting signal for germination
- Examples of dark germs
Often in connection with plant seeding of light germs and dark germs the speech. At the latest when the hobby gardener wonders why the sprouted seeds despite good care, not at all or only sparsely. Often it is because of the light or dark germs not created the right conditions and seeds were sown wrong. Therefore, it is important to understand the physiology of light or dark germinating seeds. What sounds complex is very simple in reality.
Different types of sorts
All higher plants multiply via seeds. But the seeds are sometimes very different in size and germination. One of the most important aspects for a successful sowing is, apart from the correct soil temperature and adequate irrigation, the sowing depth - it mainly depends on whether the plants are light germs, dark germs or light-neutral seeds.
The seed as energy storage
Light germs are usually recognized by the fact that their seeds are very small and light, because they have hardly any nutrients. The advantage of the low weight is that the seeds are carried away by the wind and can thus spread in a large radius. A disadvantage is the low energy reserves to feed the seedling in the first few days of growth or weeks. If the germinating seeds are covered by a thick layer of soil, only a few plants make their way to daylight. Dark germs, on the other hand, usually have larger and heavier seeds, which provide the seedling with plenty of energy to make their way through the earth to the surface.
Seeds of lupins (left) and monkshood (right) need darkening for germination
The starting signal for germination
All seeds have proteins with which they react to sunlight. If the right spectrum of light falls on the seed, it begins to germinate. This effect is called photomorphogenesis. While light germs especially use the short-wave, bright red spectral range of light for budding, the dark germs are the long-wave dark red light components that stimulate the seeds to grow. These long waves of light can penetrate the upper layer of the earth and are caught there by the seed. Since too much light inhibits the growth of dark germs, it is important to ensure that the seeds of dark germs are also covered with soil, pulp or cardboard when growing seeds in pots or seed trays.
Light neutral seeds are the least picky. These include most of the summer flowers. They thrive best under a very thin layer of soil, which protects against dehydration and drift, without darkening the seeds too much. The earth cover should be only a few millimeters for these seeds, otherwise just for very small seeds, the force is not enough to pierce them.
Examples of dark germs
Typical dark germs among the summer flowers and perennials are forget-me-not or Silberling, Lupine, Christmas rose, Eisenhut, larkspur and cranesbill. Among the cereals, corn and barley are the most popular dark germs. Many herbs and vegetables such as pumpkin, carrots, peas, corn salad, wild garlic, chives, coriander, beans, cauliflower, chard, cucumber, nasturtium and borage are also among the dark germs.
Pumpkin (left) and pea (right), like most vegetables, are dark germs
If you want to sow dark germ, you should always cover the seeds well with soil. As a rule of thumb, set the seed at least twice as deep as it is high. Before sowing, determine whether the plants are light or dark germs so that you can create the optimal planting conditions. Information about the type of seed and the optimal planting depth can usually be found on the packaging. For self-collected seeds, the size of the seeds provides a good orientation: the smaller the seeds, the flatter they should be in the soil.