Seed Stratification, 2 Ways

Some seeds, mostly perennials, benefit from experiencing a cold and damp period just like they would if outside in nature. Cold or seed stratification is the process of the seed coating slowly degrading from moisture (but not too much or they’ll rot). Once spring hits and temps warm up, the seeds will be ready to germinate. Here’s two ways to help stratify seeds:

SEED TRAYS
Sow seeds just as you would during seed starting season. Make sure soil is damp and seeds are lightly covered in soil. Place in a cold but protected location like an unheated greenhouse or covered porch. Water as needed to retain moisture. Grow light/sunshine not needed at this time.

REFRIGERATOR
Place a damp paper towel in an airtight container. Add seeds and make sure they’re well folded inside the towel. Seal the container and store in the refrigerator for 4-6 weeks, depending on seed variety. Then sow as usual.

SEEDS THAT LIKE STRATIFICATION
Perennial herbs like rosemary, sage, thyme, and oregano. Perennial kale, collards and spinach. Asparagus, strawberries, apples, plums, cherries, artichoke. Perennial flowers such as lupine, milkweed, coneflower, rudbeckia, larkspur, and more.

Note: Seed stratification can be done naturally by sowing seeds outdoors in fall. If you have mice, squirrels and critters that eat seeds overwinter, these hands on methods can be helpful.