Just as perennial plants survive the winter by going dormant (literally meaning "sleep",) seeds can have winter dormancy also. The seeds of milkweed (monarch butterflies favorite) do this, and so do the seeds of fruits, berries, and many herbs.
Seeds go dormant in nature to wait until conditions are right for survival. To break their dormancy (wake them up), the gardener needs to create the conditions the seeds are waiting for.
Many seeds are waiting for winter to be over. They don't want to sprout on a warm day in December--they want to make sure winter is really over. So each seed is programmed to need a specific period (up to 4 months, depending on variety) in cold, wet, soil before they can sprout when the soil warms. This is called stratification, or cold-conditioning, and it is a basic tool for getting seeds to break dormancy and germinate well.
It is easy to grow seeds that need cold-conditioning if you plant them now. If they are put in pots and placed outside all winter, those seeds sprout in spring, as Nature intended. If you wait and plant them in spring, you will have to put them in the refrigerator for their cold-conditioning.
Some seeds need a period of warm before the cold (This mimics the summer when they fall off the tree.) That's easy--just keep the pots indoors for a bit before you put them outside. The instructions are on the packet.
To read more about this and other tricks to germinate dormant seeds, please click HERE.
This work by Bountiful Gardens is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.