Stratification: Staging Seed for Sprout

November 21, 2018

By: Barb Holtz

Patience is not a virtue many humans have. Nature, on the other hand, doesn't bat an eye at waiting. Sure, nature can sometimes throw us for a loop, but patience is the norm.

Seeds are the poster child of patience. Seems easy to drop a packet of 'yet-to-come' and expect sprouting victory. But seed germination is a process generally out of sight and out of mind. So how does the OPN seed purchaser know what to do? Luckily, you have us! We harvest, clean, test and store for you. Our seed storage is of the cold and dry variety. This gives germ the best chance to remain viable until it reaches your soil. Then, it's up to you.

Bed your seed on bare soil or in shredded hardwood mulch free of pressure from other plants and seed bank stirring (i.e., no tilling the garden bed). The shredded hardwood mulch should be broken down to have the consistency of soil. The optimum time for sowing seeds depends on the species. Many native plant seeds require stratification, the $10 term for a cold-warm-wet or dry readying regime. As a seed passes through fall, winter and into spring, varying temperatures and humidity levels degrade the seed coat. This allows water to imbibe and begin germination. Without this for many species, growing success is limited to non-existent within that growing season.

What does this mean to you? So you bought a seed mix packet to sow in the spring. As long as your site is prepped, let the broadcasting begin. If your mix contains milkweed seeds that require stratification, it simply means that species will likely not sprout until next year or even for multiple years while it establishes underground.  The seed isn't wasted, it just wants to winter first.  If annuals and some other easier establishing perennials are in the mix, they are typically good to go.

My advice? Sow into your prepped bed in late fall after soil temperatures are below 50 degrees or frost seed in winter on frozen ground (a dusting of snow is ok) if stratification is not wanted on your garden to-do list.  Sow in spring (no later than June 1st) realizing that patience may be called upon. Either way, enjoy the ride. Once the warm up begins and green appears, we all welcome new life after winter's rest no matter how it happened.

To discover which seeds require stratification, check out the Seeds of Individual Species on our website. Also, check out this link for detailed stratification info and types.