What are the common methods for germinating flower seeds?

The germination period of seeds varies with the flower species. Some seeds need several months or even several years to germinate, but artificially germinating seeds can shorten their dormancy period.

Soaking treatment

Seeds of flowers such as redbud (Cercis chinensis), Sorbaria kirilowii and Weigela florida have a short dormancy period and germinate easily; soaking them in warm water at 40 to 60 degrees for 1-2 days allows them to be sown directly. Some flower seeds, however, have a gelatinous or waxy seed coat, such as the Chinese sumac (Rhus typhina); the seeds should first be soaked in 90-degree water, then allowed to cool naturally for 24 hours so the seed coat softens and absorbs water, prompting the seeds to germinate.

Precautions

When treating seeds by soaking, change the water frequently; the time at which the water temperature exceeds 60-90 degrees should not exceed half an hour or one hour, after which the water temperature should be lowered below 40 degrees, otherwise the seed embryo may easily die.

Low-temperature treatment

Rosa roxburghii, wintersweet (Chimonanthus praecox), forsythia, lilac and some herbaceous flowers sown in autumn need a certain period of low temperature (between 0-10 degrees) to break the dormancy of the seed embryo and prompt the seeds to germinate.

Method of operation

Mix the seeds evenly with sand at 60% humidity, put the mixture into a plastic bag, tie the bag tightly and place it in a flower pot, then bury the whole flower pot in open ground 40-60 cm deep. Alternatively, the seeds can be placed in a refrigerator at 3-5 degrees for two or three months, then sown in spring. They can also be sown in autumn, and after the seeds undergo natural freezing through the winter, they will germinate the following spring.

Variable-temperature treatment

Seeds of flowers such as fringetree (Chionanthus retusus), tree peony and Chinese peony have the habit of double dormancy of the radicle and hypocotyl; the radicle needs a month or more at 25-32 degrees to break dormancy, and the hypocotyl needs a month or more at 3-5 degrees to break dormancy. When treating such seeds, mix them with wet sand before sowing, and after a period of high temperature transfer them to low temperature.

Precautions

When seeds undergo variable-temperature treatment, make sure the high-temperature period and the freezing period are long enough, otherwise the seeds will still be difficult to sprout after sowing.