Let's talk Cold Stratification 🥶 🌱❄️
It's early February in Zone 8, and that means it's time to prepare seeds that require cold stratification to germinate!
Cold stratification is a period of 1-3 months of cold, damp conditions that many seeds need in order to recognize that conditions are right to come out of dormancy in the Spring. Many tropical plants, like most of our hot-weather annuals, don't need this treatment. However, many plants native to the Pacific Northwest require it in order to mimic their natural environment.
For cold stratification, think:
-🫐Native bushes (snowberry, oregon grape, serviceberry, etc)
-🪻Native flowers and bulbs (Lupine, camas, milkweed)
-🍎Cool-weather Perennials (strawberries, chives, some fruit trees)
Methods:
-🍁Fall sowing - Simply scatter the seeds where you want them to grow during the fall or winter, cover very lightly and don't plant on ice or snow. Can also plant in very early spring, but want 1 month minimum of very cold weather left
-🌬Dry refrigeration - Put the seeds in the fridge or outside (somewhere dry and in the shade!!) for at least 1 month
-🌧Wet refrigeration - Place seeds in a plastic baggy with a damp paper towel for 1 month, check for mold or rot
-❄️Winter sowing - Plant seeds in the late winter/very early spring in winter sowing jugs; we'll discuss this method more later this week!
I have a handful of seeds for sale LOCALLY (Willamette Valley) that need cold stratification, so need to be planted soon! Contact me if you're interested in some - $3 each
-Oregon Grape
-Serviceberry/Juneberry
-Italian Plum
-Agrimony
-Evening Primrose
-Purple Foxglove (2nd year blooming)
-German Chamomile
-Mullein
[ID: Picture demonstrating a method of outdoor cold stratification, winter sowing - plastic juice bottle is half filled with soil and taped back together, "Agrimony" on the label]











