Seed stratification: plants that need to be cold before germinating

Throughout the history of plant evolution, plants have had to adapt to the many changes that have occurred on Earth. One way to achieve a higher germination percentage and, therefore, a greater number of specimens that adopted a great variety of trees and shrubs was get used to the cold to be able to wake up in spring.

This curious fact is very necessary so that we can currently enjoy the beauty of a large number of plants. Therefore, those of us who want to cultivate non-native species in slightly warmer regions will be forced to make them feel cold. How? By means of the seed stratification in the fridge.

What is seed stratification?

The seeds, once they fall to the ground, are immediately covered by the earth blown by the wind, and by the leaves that the adult specimens fall. Thus, they remain protected during the colder months, with a temperature that is not high enough to wake it up, nor low enough for the embryo inside it to be harmed. After a few months, the sun warms the ground again and, with the arrival of the rains, its time has finally come.

In cultivation, a way to emulate natural conditions is by sowing the seeds in a tupperware with a very porous substrate (perlite with a little black peat for example) and placing it in the refrigerator at about 6ºC. It's very important open it from time to time so that the air is renewed and thus prevent the proliferation of fungiThus, we will have the seeds more controlled. Time will vary by gender, but generally must remain in the refrigerator for a period of 2 months, 3 maximum.

Now, you can also sow the seeds in a seedbed and leave them outside if winter is cold in your area (below 7 ° C).

Plants to be stratified

There are many plants that need to be cold before germinating. Among them, we highlight:

• All kinds of Arces, such as Japanese maple or false banana
• All kinds of Prunus, such as Japanese cherry or almond
• All kinds of conifers, such as yews, cypresses, pines ...
• Some carnivores, like the Drosophyllum
• Olmos, including Chinese elm

Thus, the stratification of seeds is vital so that a greater number of seeds can germinate, and you can enjoy more specimens 🙂.