How to germinate flower seeds? A detailed guide to practical methods

I. Variable temperature method Some flower seeds, such as fringetree (Chionanthus retusus), pea tree (Caragana), tree peony (Paeonia suffruticosa), and Chinese peony (Paeonia lactiflora), have a double dormancy habit involving both the radicle and the hypocotyl, that is, their radicle (the part of the embryo that develops into the root) must go through a high-temperature stage of 25°C-30°C for 1 to 2 months or longer to break dormancy, while the hypocotyl needs 1 to 3 months at 3°C-5°C to release dormancy. For these seeds, before sowing they must be mixed with moist sand, subjected to a certain period of high temperature, then transferred to low temperature; after variable temperature treatment, they can germinate quickly when sown in spring. But note that during treatment, the durations of the high-temperature period and the low-temperature period must be ensured, otherwise the seeds will still be difficult to sprout after sowing.

II. Water soaking method For seeds with a short dormancy period that germinate easily, such as redbud (Cercis chinensis), Sorbaria kirilowii, and Weigela florida, soaking the seeds in warm water at 40°C-60°C for 1 to 2 days allows direct sowing. For seeds such as staghorn sumac (Rhus typhina), soak them in 90°C water, let them cool naturally for 24 hours to soften and hydrate the gelatinous and waxy seed coat, and then they will germinate. But note that when treating seeds by water soaking, the water must be changed frequently, the time at which the water temperature exceeds 60°C should not exceed half an hour, and afterwards the water temperature should be lowered to below 40°C, otherwise the seed embryo may die.

III. Low temperature method Some flower seeds, such as chestnut rose (Rosa roxburghii), wintersweet (Chimonanthus praecox), forsythia (Forsythia suspensa), lilac (Syringa), and some herbaceous flowers sown in autumn, need a certain period of low-temperature treatment (0°C-10°C) to break embryo dormancy and germinate. The method is to mix the seeds with sand at 60% humidity (it forms a ball when squeezed by hand and falls apart when released), then put the mixture in a plastic bag, tie the opening tightly, place it in a flower pot, and then bury the pot together with the soil in open ground 40 to 60 cm deep. The seeds can also be placed in a refrigerator at 3°C-5°C for 60 days-90 days, then taken out and sown in spring. Or sow in open ground in autumn, so that the seeds experience the natural low temperatures of winter outdoors and germinate and emerge the following year.