Can be started in flats in late January if you have the space & lights: Lemongrass, Leeks. Onions, Lavender, Eucalyptus
Start cold stratification on:
Bunchberries, Boneset, Goldenrod, Woodland Sage, Wild Lowbush Blueberry, Bottle Gentian, Liatris, Milkweeds, Lavender, Delphinium, Columbines, Plantain, Sweet Cicely, Wild Yarrows, Strawberries, Maral Root, Pincushion Flower
Can also be started in flats: Luffa, Lisianthus, Artichoke, Foxglove, Columbine, Ginger
Seeds, Paper towel, Sharpie, Plastic Bag (or beeswax wraps)
Wet paper towel
Wring out to the dampness of a sponge. You don't want excess water increasing seed molding, but also enough moisture so seeds can absorb some moisture and stay wet. Fold paper towel neatly into a rectangle. Lay flat on a clean surface.
Sprinkle seeds on one side o the paper towel in a single layer.
Ensure paper towel is still moist enough. If not, spray with water.
Fold the empty side of the paper towel over, covering the seeded side completely.
Label the plastic bag with a sharpie or other durable and waterproof marker. I like to put the variety and date the stratification started. If I have time, I will add the end date on there too.
Place the folded paper towel into the bag gently, making sure no seeds spill out. I don't seal the bags airtight, as sometimes that leads to soggy paper towel, which can rot your seeds.
Place the baggie in the fridge in a low traffic area, where they will not be disturbed. (NOT the freezer)
I check on the baggies weekly. Some may need a little extra water. Some may need to be wrung out a little.
I also open the bags up to make sure no seeds are growing mold or getting mushy, or to ensure none have prematurely germinated.
When it's time to remove the baggies from the fridge to germinate, I take them out and allow them to come to room temperature before opening up and disturbing. Then the paper towel can be removed from the bags, and you can plant seeds as you normally would. Some folks even leave the seeds in the paper towel to germinate under lights by checking daily for any germinated seeds. Once seeds have germinated they are gently removed from the paper towel and plant into potting soil.
USDA Zone 3a: to -39.9 °C (-40 °F)
USDA Zone 3b: to -37.2 °C (-35 °F)
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)