Sowing time varies from herbaceous to woody plants, and each requires different conditions for germination. Usually the time of sowing the seeds of herbaceous plants depends on the production schedule and more importantly the temperature required for seed germination. Therefore, the minimum required temperature for germination of seeds of these plants is very important and this is a basic need. For example, the minimum temperature required for germination of lettuce seeds, cabbage leaves and green peppers is zero, 10 and 16 ترتیب C, respectively.

Seed planting time in woody (permanent) plants depends on several factors such as seed recession conditions, temperature required for germination and management and the geographical location of the treasury, so there are differences between the time of seed sowing of these species. In this regard, woody plants are divided into the following four groups:

Seeds that should be sown immediately. These seeds arrive in spring or early summer, such as some maple, poplar, and elm species.

Seeds that should be planted in the spring, such as acacia, European pine and Christmas tree. These seeds germinate at a temperature of 32-15. C.

Needle seeds such as pine and maple and many deciduous woody species that need moist refrigeration for germination but do not germinate until the soil temperature is high after cooling. The required temperature for germination of this type of seeds is 20-30. C and the time of planting them is in autumn.

Seeds of some species, such as apples, pears, and kernels, require moist cold to germinate and germinate at a temperature of 170-110. C after adequate cooling. These seeds are grown in the fall. But the seeds of fruits such as cherries and sour cherries, which have a hard crust and encode the fetus, should be planted in late summer or early fall so that they are exposed to hot weather for 6-8 weeks (before the onset of winter cold) or The seeds should be harvested before full ripening and planted before drying to increase the percentage of germinated seeds.