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Posted By American Meadows Content Team on Mar 7, 2018 · Revised on Oct 2, 2025
by Amanda
Many native varieties, like Prairie Coneflower, require cold stratification if seeding in spring. The good news is this is an easy process for any gardener.
Many wildflowers—especially native varieties—have clever mechanisms in place that help protect them from germinating too early in the spring or too late in the summer. These varieties re-seed naturally in the wild and stay dormant until the proper time for them to start sprouting. More and more gardeners are seeing the benefits of growing native varieties in their landscapes and with a simple technique called cold stratification, you can easily add these wildflowers to your garden in the spring.
Dig in! Jump to a section to learn more.
Many annual varieties, like Zinnias, and Sunflowers, have soft shells and can simply be sprinkled on bare soil in the spring. But some perennials, especially native wildflowers, have a hard coating that helps protect the outer shell from breaking and sprouting too early. We’ve all experienced an unseasonably-warm spell in in the middle of January or February — this mechanism helps prevent the seeds from being tricked into coming out of dormancy until it’s just the right time.
The good news for gardeners is that the natural cold stratification needed for germination can be forced with just a few materials, water, a refrigerator, and patience.
If you’re planting native wildflowers or varieties that require cold stratification in the fall, this step isn’t necessary. Nature will do what it does best during the winter months and cold stratify the seeds for you.
There are quite a few native varieties that should be cold stratified before planted in spring. We chose Prairie Violet Seeds, St. John's Wort, and Tennessee Purple Coneflower as some of our varieties to plant.
There are several perennial and native seed varieties need to be manually broken from dormancy in order to sprout and thrive in your garden. If you’re planting native seeds and aren’t sure, chances are you should at least scarify and soak your seeds before planting.
Learn how to scarify and soak seeds for spring planting.
Common varieties that require cold stratification for spring planting:
Although this is a comprehensive list of the most common varieties, there are other seeds that do require cold stratification before spring planting. It’s best to call us at (877) 309-7333 if you aren’t sure.
Most of the materials you need to cold stratify seeds can be found in your home or tool shed.
Cold stratification is an extremely easy process and once you’ve done it once, you’ll no doubt get the hang of it. The first step is to gather the materials needed, all of which can be found in your home, tool shed, or with a quick trip to the hardware store.
Materials for Cold Stratification:
Now that you have your materials, you can use three different methods for cold stratifying your seeds. All three of these methods work equally well and offer up different ways to basically keep the seeds moist in your refrigerator until it’s time to plant. We’ll go over all three methods:
This method is very similar to the sand method, but uses peat moss (which many of us have lying around somewhere).
This is one of the methods most widely used for native seeds, especially milkweed. It is easy, quick, and the materials are usually right in your kitchen ready for use.
The time you need to keep your seeds in the refrigerator depends on the variety, but 4-5 weeks should be a sufficient amount of time for most seed varieties. Once there’s no more chance of frost in your area, take your seeds out of the fridge and spread seed on bare soil as normal. The simple, quick process of cold stratification helps the seed germinate quicker and grow more readily in your garden bed.
