Having discussed snowdrop genetics, breeding and fertilisation, it is of course essential to get an idea how to germinate the seeds that we might derive from our efforts.
Seed germination in snowdrops, at least in G. nivalis, has been the subject of scientific research (1,2). It is found that the common snowdrop germinates best when kept in a dark, moist environment directly after taking the seeds from the plant. In a study by Newton and colleagues, the best temperature preceding germination was 20 °C (68 ° F) over approximately 12 weeks, with a subsequent germination temperature of 15 °C (59 ° F). This mostly agrees with observations from gardeners. The only key difference being that most gardeners will place the seeds in conditions where they will be exposed to normal outside weather.
General recommendations include picking the seed pods when they turn yellow (3). Seed development takes place in G. nivalis from mid-February to mid-May (2). Subsequently seeds should immediately be placed and kept in moist conditions underground and exposed to normal weather. When started like this, most seeds should germinate in the first year after sowing.
Embryos elongate at the higher temperatures of summer, causing seed dormancy to decrease (2). In autumn, the first part of the seedling (radicle) will emerge with temperatures around 15 °C. The seedlings continue to grow and develop at the lower temperatures of the winter, emerging around January for G. nivalis.
Embryos elongate at the higher temperatures of summer, causing seed dormancy to decrease (2). In autumn, the first part of the seedling (radicle) will emerge with temperatures around 15 °C. The seedlings continue to grow and develop at the lower temperatures of the winter, emerging around January for G. nivalis.
Considering germination inhibitors
It is believed that many seeds contain germination inhibitors. Some of these inhibitors will only be broken down after some weeks in normal summer/autumn weather, i.e. by high temperatures. Others will only be broken down after some weeks in cold weather, i.e. a cold period of winter. Most observations seem to agree that for snowdrop only a warm period at about 20° C is required however.
Other types of inhibitors might be released after a good soaking in water before sowing.
Finally, in snowdrops there appears to be a requirement for the seeds to be in the dark. Germination is likely inhibited by light. For this reason, some recommend sowing seeds of Galanthus and Narcissus underneath a layer of compost and grit (4).
After germination, the seedlings might best be protected in case of extreme weather like frost, heavy snow- or rainfall. Seedlings in their first years will look like grass and might take 4-6 years before flowering.
As a final fact of interest; On average, a seed pod of G. nivalis holds only 6 seeds (1).
1. Newton RJ, Hay FR, Ellis RH.Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus continues post-shedding with little evidence of maturation in planta https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3631335/ Ann Bot 2013 May; 111(5):945-955.
2. Rosemary Newton. Environmental factors controlling wild daffodil and common snowdrop seed germination. Daffodils, Snowdrop and Tulip Yearbook 2015 page 37-39
3. Axel. Observations and theory of Galanthus germination. SRGC.net
4. Ian Young. Growing bulbs from seed. SRGC.net
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