How to germinate flower seeds? These key points you need to know

Different types of flowers, because their seed coat structure and physiological mechanisms differ, also have different germination periods. For example, scarlet sage, China aster, garden balsam and the like will sprout quickly as long as they are sown at the right time. But some flower seeds need several months or even several years to germinate, so artificial germination must be carried out to shorten the seed dormancy period.

1. Soaking treatment For flower seeds with a short dormancy period that germinate easily, such as redbud, pearl spiraea and weigela, soaking the seeds in 40°C warm water for 1-2 days allows them to be sown directly. For seeds such as staghorn sumac, first soak them in 90°C water, then let them cool naturally for 24 hours, so the seed coat softens and absorbs water before they can germinate. But note that when treating seeds by soaking, the water must be changed frequently, and the time at a water temperature above 60°C should not exceed 0.5-1 hour; after 1 hour the water temperature must be lowered, generally to below 40°C, otherwise the seed embryo is liable to die.

2. Low-temperature treatment Some flower seeds, such as chestnut rose, wintersweet, forsythia, lilac and some herbaceous flowers sown in autumn, need a certain period of low-temperature treatment (0°C-10°C) to promote after-ripening, break the dormancy of the seed embryo and germinate. Method: mix the seeds with sand at 60% moisture, then put them in a plastic bag, tie the opening tightly, place it in a flower pot, and bury the pot together in open ground 40-60 cm deep. The seeds can also be kept in a refrigerator at 3°C-5°C for 60-90 days, then taken out and sown in spring. They can also be sown in autumn, so that the seeds go through natural freezing outdoors in winter and can germinate and emerge in the following spring.

3. Alternating-temperature treatment Some flower seeds, such as fringetree, tree peony and Chinese peony, have the habit of double dormancy of the radicle and hypocotyl, that is, their radicle needs 1-2 months or longer at a high temperature of 25°C-32°C to break dormancy, while the hypocotyl needs 1-3 months at 3°C-5°C to break dormancy. For this type of seed, before sowing it must be mixed with moist sand, subjected to a certain period of high temperature and then transferred to low temperature; after alternating-temperature treatment, sowing in spring can bring rapid germination. But note that during treatment, the durations of the high-temperature period and the cold period must be ensured, otherwise the seeds will still be difficult to germinate after sowing. (Li Wenjuan)