Stratification: Some Seeds Need Cold to be Started Successfully

Some plant species require a cold period in order for their seeds to germinate and/or successfully thrive. The seed utilizes the cold to break down the seed coating. In other cases, the seeds germinate with warmth and moisture, but some prefer to sit out in the cold as their seedlings develop. Most of the time, details on cold stratification requirements for specific plant species can be found on the back so seed packets.

You can sow cold loving seeds outdoors in trays under protection from heavy rain, snow and wind like under a covered porch or in an unheated garage. You can also mimic nature's cold temperatures by placing seeds in a container in the refrigerator as shown in the video.

Here’s several examples of plants that require cold (typically around 40 degrees Fahrenheit and under) in order to get established:

Fruit and Vegetables
Strawberry, Artichokes, Crabapple, Cilantro, Goji, Hops, Mulberries, Quince, Apple, Ramps,

Flowers and Shrubs
Dogwood, Southern Magnolia, Delphinium, Columbine,
Clematis,
Monkshood,
Lady’s Mantle, Butterfly Bush,
Sunflower
Geranium (perennial),
Lavender,
Hibiscus, Heuchera, Rudbeckia,
Sedum,
Viola,
Pincushion flower,
Globeflower, Autumn Olive, Bachelors Buttons, Milkweed, Heather, Hollyhocks, Lupine, Osage Orange, Perennial sunflowers, Rose

Herbs
Arnica, Anise Hyssop, Bergamot, Black Cohosh, Chamomile, Chives, Elderberry, Echinacea, False indigo, Ginseng, Lemon Balm, Licorice, Lavender, Marshmallow, Mullein, Oregano