Sowing is the most widespread method of plant multiplication. This reproduction technique is called gamica multiplication, ie by means of seeds, and differs from agamic multiplication, consisting of other types of multiplication (including for example cuttings, grafting, offshoots, etc.). The most significant difference between these forms consists in the fact that while the plants obtained with gamica multiplication are usually very similar to the plant that generated the seeds, but they can also differ significantly from it, vice versa the subjects obtained by agamic way have identical characteristics to that of the mother plant.
Sowing: Types of sowing
Because the sowing allows to obtain good results it is necessary to have seeds of high germination and endowed with great germinative energy. By germination we mean the property of germinating, which the seeds retain more or less for a long time. With the term germinative energy, instead, we refer to the vigor with which the seed gives life to the new plant. It can happen, therefore, that a seed, although able to germinate, has little vigor, and this usually depends on the lack of freshness of the seed. Wherever possible, therefore, it will be preferable to plant seeds of the last season.
Sowing can be done outdoors or in boxes or terrines, depending on whether the species to be sown are rustic or delicate. Outdoor sowing is carried out in previously prepared flower beds. For this purpose it will be good to dig the soil, remove the weeds and add sand and garden soil.
Seeding in seedbeds, on the other hand, is carried out using special composts suitable for sowing. To obtain a balanced mixture the following proportions are generally followed: 1 part of garden soil, 1 part of sand and 1 part of peat. On the bottom of the bowl or of the seedbed you will have to place some draining material (ex. Shards, pebbles, gravel, etc.).
Sowing depth. Seeding depth must be very limited. The smaller seeds must be scattered on the available surface. These seeds should not be covered, as moisture could cause them to rot.
The larger seeds, on the other hand, must be covered with a layer of soil equal to their diameter. Some seeds, however, can also be planted deeper (for example beans or peas can be planted at a depth of 3 times their diameter).
Tips. It may be appropriate, sometimes, after sowing, to roll the soil to make the seeds adhere to the soil.
In order to allow better homogeneity in the sieve, the smaller seeds are usually mixed with sand.
The first spring sowing must be protected from the cold by covering the seed-beds with glass plates or sheets of non-woven fabric. The protection can be eliminated when the seeds have germinated.
To water the compost we use irrigators with a very fine jet. If the sowing takes place in containers or terrines, the containers can be immersed until the soil is moistened.