Fall and Winter Seeding

Can you seed native plants in the fall and winter? —The short answer is Yes! In fact, there are a lot of advantages to seeding during the non-growing season. Understanding when and how to seed in the off-season can increase seeding establishment options, and improve seeding results.

*Note—we will be discussing native seed mixes here (ie. seeding for pollinator gardens, pocket prairies, habitat restorations, etc.), not turf or standard lawn grass.

If you are looking to establish a new native planting from seed, or you’re looking to seed into an existing area to increase species diversity or fill bare patches, there are two winter seeding options for you—dormant seeding and snow seeding.

Dormant Seeding

Dormant seeding involves seeding during the beginning of the dormant season, typically the end of fall and beginning of winter. For dormant seeding, seed is scattered when soil temperatures are cold enough to prevent germination. The seed stays in the soil, dormant, until spring. The spring temperatures warm the soil and break seed dormancy, initiating germination. There are many benefits to this process. For starters, many native seeds require something called “cold stratification.” Native seeds have evolved to survive Minnesota winters by not germinating until they experience cold, wet conditions. Winter conditions break the seed coat, allowing the seed to germinate upon the spring warm-up. This way, seeds don’t germinate upon maturity in summer, only to be killed by the harsh winter. Essentially, the freeze-thaw cycle is necessary for some native seeds to germinate. There are ways to manipulate this cycle artificially, but if you’re seeding an outdoor area, why not take advantage of the natural cycle? Species that are seeded in the fall undergo the full freeze-thaw cycle, ensuring any requiring cold stratification are naturally set up to germinate in the spring. Conversely, when these species are seeded in spring, they may sit dormant for a year until they experience a winter season.

Additional benefits include a longer growing season out of the gate. Many native plants will start to grow in late April-early May (depending on the seasonal conditions). Spring seedings often wait until mid-May due to wet spring conditions. Therefore, dormant seeding can give seeds a few extra weeks of growth to get their roots better established for the hot, dry summer ahead. Also, dormant seeding can be easier on you. The dormant seeding period can be longer than spring seeding periods, lasting well into December and giving you more time to get your seeding done. Finally, dormant seedings can take advantage of early spring moisture from snow melt and rain, which can save you a few weeks of watering.

How to Dormant Seed

Dormant seeding is relatively simple. The biggest catch is making sure you seed at the right time. Dormant seeding only works if the seed stays dormant. If the soil temperatures are too warm, the seed (that doesn’t need cold stratification) may germinate and die in the winter. To dormant seed, wait until soil temperatures are consistently below 50 degrees Fahrenheit. Consistently is key. Soil temperatures may drop below 50F, only to rise again during a warm spell. Ideal soil temperatures are 40F, as that is too cold to likely raise above 50F, but warm enough the soil has not frozen. In Minnesota, soil temperatures are usually right for seeding from November-December. In recent years, this timeframe has been getting pushed later. For instance, this year, soil temperatures in the Twin Cities area were not consistently cold enough until the 3rd week of November. Where you are located in the state will determine when soil temperatures are right for you. Many groups such as NOAA, MN Dept. of Agriculture, and university extension programs track soil temperatures. So it’s relatively easy to look up soil temperatures close to your region online.

Like spring seeding, it is important to have a good seeding prep. Seed-to-soil contact, or the ratio of seed surface area touching soil, is important. You need high seed-to-soil contact for a successful seeding. Depending on where or what you are seeding, this may involve raking, tilling, disking, burning, or using a no-till drill seeder. If you are converting from turf, sod cutters and mechanical removal are options as well. Finally, herbicide application to kill existing vegetation may be an option on some sites. If you are inter-seeding into existing vegetation, consider ways to create space for the seed by raking or mowing the current vegetation short.

When you have good site prep and soil temperatures are consistently below 50F, you are ready to seed. Broadcasting or drill seeding are both viable options for dormant seeding. If broadcast seeding, you can seed on top of a light snowfall and let the seed sink into the soil as the snow melts. Otherwise, try to seed right before a thick snowfall. The snow will pack the seed into the soil, and protect it from birds and other wildlife. You do not need to water native seed right away after dormant seeding.

Snow Seeding

Snow seeding is a variation of dormant seeding that occurs in late winter, typically February-March. Snow seeding has the same advantages of dormant seeding, and the overall goal is the same. The major difference between the two is the timing. Since snow seeding happens much later in the winter, there can be greater variability in good seeding days. You may not always have the right conditions for snow seeding, and depending on the snow accumulation and timing of spring warm-up, your seeding period can be short. Finally, to be successful with snow seeding, your timing and weather conditions need to align perfectly.

When snow seeding, seed is broadcast directly on top of snow, melts through the snow, and is sealed into the snowbank upon refreeze. Once the snow fully melts in the spring, the seed drops into the thawing soil. Since snow seeding relies on snow melt, it has to occur when there is enough daytime with above freezing temperatures to melt the top layers of snow. As the top layers of snow melt, the seed drops into the bottom layers, eventually moving into the soil. If there is not enough warmth to melt the top snow, then the seed stays stuck on the snow surface, and may be subject to browse frow wildlife.

How to Snow Seed

Since you cannot see or access your top soil when snow seeding, it is important to make sure your seed prep is finished before snowfall. Ensuring that the seed will contact soil upon melting through the snow is still an important step. Make sure you have good site prep, utilizing any of the techniques mentioned above. Next, pick a sunny day with above-freezing highs. You will need to get the seed on the snowpack before the daytime temperatures peak. That way, when the temperatures raise enough to start melting the top layer of snow, your seed is already in place. If you seed too late, there won’t be enough time for the seed to melt through the top snow before temperatures drop again in the evening. Snow seeding typically occurs in February or early March, but this can vary across years. Finally, snow seeding is not an option for drill seeding, as the ground will be frozen.

Final Words

So, if you’re looking at seeding native species this year, consider a dormant seeding. Right now, most of Minnesota has the right conditions for dormant seeding. Our crews started seeding projects across many public lands and private residences this week, and we’re looking forward to another couple weeks of good seeding conditions. If you need help with seeding, or have questions about seeding for native habitat restoration or landscaping, let us know! We’d love to help you realize your seeding goals.