Pagoda dogwood branch with leaves, Cornus alternifolia.

Ontario Native Plant Growing Guide for February

At the beginning of February you still have time to winter sow your native seeds, or put them into cold, moist stratification, but your window is quickly closing. If your seeds have already been stratified you might want to take them out of the fridge and sow them under lights.

If you’ve never heard of cold, moist stratification, do not worry! The seeds of many of Ontario’s native plant species are dormant, which protects them from germinating during a warm spell in the winter. In order for them to germinate they need to spend two or three months in damp and cold conditions. The moisture signals to the seed that it is in a place where it will be able to grow, and the cold temperature tells the seed that it is winter time.

Direct Sowing

There are a few ways to break the dormant state of the seeds so that they will germinate and grow. The first is to sow the seed directly in the ground in the fall before the ground freezes (October-November). The seeds will naturally experience winter and then germinate in the spring. Since it is February, we’ve missed the window on that method.

Winter Sowing

The second is called ‘winter sowing’. With this method you plant the seeds either in milk jugs or in pots inside a ventilated container and place them outside in the snow for two or three months. The ventilated container protects the seeds from rodents and provides a mini greenhouse in the spring. Early February is not too late for winter sowing. By March the window for winter sowing ends as the seeds will not have a long enough period of cold to break their dormancy.

Winter sowing native plant seeds in February in a ventilated container outside.
Winter sown native plant seeds in a container in a snowbank.

Cold, moist stratification in the fridge

The third method uses your fridge to provide the cold, moist winter conditions. This method involves mixing the seed with some damp vermiculite in a sealable plastic bag and placing it in the fridge. After two to three months you can take the bag out of the fridge and sow the seed/vermiculite mixture.

Growing native plant seeds by breaking dormancy in the fridge.
Cold moist stratification of native plant seeds by putting them in the refridgerator.

Wild Plants from Seed is a great resource for seed treatments. Check it out if you aren’t sure what treatment your species requires.