Sowing is a generative, ie sexual, type of propagation in which the new plant is extracted from a seed. With this type of propagation, most plants in nature ensure their offspring and survival. In the seeds, the genetic material of both parents is recombined. The resulting offspring are never absolutely identical to their parents – thus preserving the genetic diversity of nature. From the small seeds grow after some time under suitable soil conditions replicable plants. Especially in game species of woody plants and perennials as well as annuals of summer flowers and seed-resistant vegetables, sowing as a propagation method in the garden plays a major role.
Good to know: The opposite of a generative propagation is the vegetative (asexual) propagation, in which a nearly identical plant, a clone, is drawn from one part of the plant – be it via cuttings , offshoots, sinkers or sticks . This type of propagation is often resorted to if one wants to preserve the characteristics of the mother plant.
Selection and storage of the seed
Seed-resistant varieties are grown over years for specific characteristics such as color, taste and shape through crossing and selection. If these varieties are multiplied by their seed, plants with exactly the same characteristics are obtained in the following generation. In contrast, there are so-called F1 hybrids, which have emerged from a cross between two homozygous parents. You get uniform offspring. The seed for F1 hybrids is more expensive than conventional seeds, but has the benefit of producing higher yields and better quality fruit. The disadvantage of such plants is that the offspring – the so-called F2 plants – may no longer have these positive properties. Therefore, F1 hybrids are not suitable for seed harvesting. Instead, use seed-proof varieties.
Even if packaged seed bags are cheap in the garden trade, it is worthwhile to harvest your own seeds : In this case, you can be sure that the plants thrive well at their location and have already proven themselves. The harvest time of the seeds has come when the plants voluntarily give up the small grains. With the help of an unused, air-permeable teabag, you can catch the seeds before they hit the ground. Simply put a bag over the seed pod of the plant and attach it to the stalk. If the capsule bursts, the grains end up in the tea bag. For self-fertilizers such as tomatoes and peas , the seed harvest is the easiest: For example, with tomatoremove the seeds directly from the pulp .
To store the seeds until next spring, clean them first and then dry them in a cool and cool place. The best way to store the grains in a screw or paper bag. In addition to the name of the plant, it makes sense to note the harvest year of the seeds. Tomato seeds remain germinable for up to eight years, while the seeds of the carrot only germinate for one to two years.
The right sowing time
In the house is usually not started before the first of March with the sowing. The reason for this is that it is usually too dark during the daytime. Since this is often the case even in March / April, it is recommended to illuminate the seedlings in addition. Otherwise, the seedlings form long thin stems with small, pale green leaves – this process is called warping. In the greenhouse and cold frame you can sow your flowers and your vegetables a little earlier, as the plants are better exposed there. There, the ratio of light and temperatures can be controlled more easily. In the case of direct sowing of flowers and vegetables in the bed, the sowing date depends on the winter hardiness and the germination behavior of the respective plants. Plan the sowing of beans, for example, so that the plants do not germinate in front of the ice saint.
Plants with a long development time such as cabbage and heat-requiring species such as cucumbers are preferred, since otherwise for these plants, the growing season outdoors is barely sufficient to retract a rich harvest. This means that the seed is first sown under glass to later plant the seedlings in a robust development stage into the open. For this one uses so-called seed boxes, small pots and Multiplattformen as well as special culture vessels, which are filled with suitable earth. This should be germ-free, nutrient-poor and very fine. Such a special cultivation soil is commercially available, but can also be easily mixed by yourself . The seeds are spread or laid out. AroundTo avoid mistakes when sowing vegetables , you should carefully pour the fine grains with a small-pored watering can attachment or with a nebulizer, so that they are not washed away. After sowing, you should press the seeds with a wooden board and sift with a thin layer of sand. The planters now get a bright and warm place on the windowsill, in the cold frame or in the greenhouse . Even classic balcony flowers such as petunia or industrious Lieschen must be pre-cultivated under glass so that they bloom in time in May.
The germination behavior of plants
In some plant species, a cold and frost effect is necessary to start the germination. Because the seeds contain a plant hormone, which inhibits germination and is slowly degraded at low temperatures. The hormone protects the seeds to germinate even before the onset of winter. The so-called cold germs are sufficient for this process only a few weeks with temperatures between zero and five degrees Celsius; These plants include, for example, maple (Acer), ornamental quince (Cheonomeles) and primroses (Primula) and tulips (Tulipa). On the other hand, strong frosts are needed to obtain the seeds of Gentian (Gentiana), Adonis (Adonis), Eisenhut(Aconitum) and Christmas rose (Helleborus) to break the dormancy. Accordingly, such plants, which usually come from the high mountains, referred to as frost germ. Frost and cold germs are sown in the autumn and overwintered outdoors – but you can also sow them directly in winter. Alternatively, you can simulate this cold stimulus in the freezer. Put the seeds in small pots and wrap them in a plastic wrap. Then put in the freezer for a few weeks – cold germination enough refrigerator. Then the actual sowing takes place outdoors.
In addition to moisture and heat, light also plays a crucial role in germination. While the seeds of some species require light, others germinate only in the dark. Seeds of so-called light germs – for example carrot, lettuce and sage – are merely scattered on the growing soil and lightly squeezed. Until germination, the seeding vessel must be in a bright place. Dark germs – for example Larkspur and Eisenhut- are scattered on the substrate and übersiebt with fine soil. In addition, you can cover the seeds with cardboard or even sprinkle them in the field in small grooves and cover with some soil. As soon as the first leaves appear, dark germs need light to grow. If you are unsure of the germination conditions of a plant, use the following rule of thumb: Cover all seeds with a layer of sand or soil that is no more than one to two times larger in dusty seed and three to four times greater in larger seeds.
Seeds of yew (Taxus) and witch hazel (witch hazel) germinate under natural conditions only after several years. Because of this delay, professional horticulture uses a process called stratification . To do this, mix the seeds with a little damp sand and then store the mixture for several weeks or months at temperatures around five degrees Celsius, before the seeds are sown in the spring. To facilitate the swelling, you can roast hard-shelled seeds lightly with sandpaper.
Tips and tricks for sowing
For sowing in pots or trays you should only use special growing soil such as coco substrate. It contains in contrast to normal potting soil few nutrients. As a result, the seedlings are initially not overfed, but form strong roots. After a few weeks, the plants need regular fertilizer, so they grow well. High quality seeding soil is sterilized with hot steam during production to kill fungal spores and other pathogens. Tip: Fill your seeding vessels half with conventional potting soil and spread an equally thick layer of growing soil on top. The young plants grow directly into the nutrient-rich soil layer.
In order for the seeds to germinate well, they need sufficient heat and high humidity. Especially when sowing on the windowsill, the seedlings often suffer from too dry indoor air – here, a covering of the seeds is particularly important. It is therefore best to use special nursery boxes or mini greenhouses with a transparent lid that allows the light to pass through, while keeping the humidity inside high. Do not forget to open the covers daily for several minutes. Otherwise, the air exchange can not take place properly and the risk of fungal infections increases. In addition, regularly check the humidity of the soil – the seeds must not dry out during germination.
Who sows his plants in seed trays, must singulate the young plants in time – this step is called Pikieren. Basically, the earlier the plants are isolated, the better they grow. The optimal time for piking is when the seedlings form first cotyledons. Gently hold the plantlets with your fingers on the leaf head and lift the root system out of the ground with a suitable stick. Now the young plant is transferred to a larger pot. Otherwise, the seedlings in the sowing shells quickly make each other’s light and nutrients controversial and it can lead to growth disorders.
Many perennials and summer flowers as well as most types of vegetables such as radishes and spinach can also be sown directly into the prepared beds as soon as the optimum sowing time for the respective species has arrived. A preculture under glass is not necessary here. The soil is well loosened before sowing and fertilized if necessary. Sowing is wide-boiled or in rows. Then pour the seeds carefully with a fine stream of water.
When sowing in rows, you can not only comply with the recommended row spacing with the help of a planting line, but also ensure a straight-line cultivation. For optimal use of space, the plants of adjacent rows should always be offset from each other. In practice, the uniform sowing of fine seeds often proves difficult. In this case, the following trick helps: Mix the seeds with the finest possible, dry quartz sand and then sprinkle the sand-seed mixture on the bed. When sowing flat, you can fill the seeds in a kitchen or tea strainer with a suitable mesh size and then sprinkle like icing sugar on a cake.
Important accessories for sowing
In order for the sowing to succeed, you will need the following items: A mini greenhouse is an ideal alternative to the conventional greenhouse, as it is space-saving and practical – it is well suited for the pre-cultivation of the seedlings. The cultivation of many young plants succeeds in so-called multi-pot plates. Here you can sow both the seeds directly into the pots, as well as pecking in small seedlings. So that you can comfortably stand upright while working, a planting table is recommended.
Another important accessory for the cultivation of young plants is the Pikierstab. This helps in the proper separation of the plants. Seeders enable even seed placement into the soil and save time. Also useful are seed discs and bands, as seeds are sown directly at even intervals on a fast-rotting specialty paper. When using it is only to be noted that the sowing aids are in constant earth contact, so that the seeds do not dry out. After laying, they are moistened and finally pressed into the ground.