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The Best Time to Plant Grass Seed in Minnesota

Achieving a lush, beautiful, green lawn you can be proud of isn’t something you can just expect to happen on its own. Knowing the best time to plant grass seed in Minnesota can save you a lot of time and money while delivering the kind of lawn you can sit in a rocking chair and enjoy all day.

Man examining healthy green grass lawn

Understanding Minnesota’s Growing Zones

The plants that thrive in Minnesota are ones that can handle colder temperatures. According to the USDA Hardiness map, Minnesota’s northern regions include growing zones 3a and 3b.

The middle portion of the state has growing zone 4a. Then in the south is growing zone 4b. And just at the southern, most part of the state is a small area that falls into the 5a zone.

You can also find out your specific zone by searching for your zip code in this online USDA Hardiness Map.

a handful of grass seeds

When to Plant Grass Seed in Minnesota

Since seeding your lawn takes time for results to show, timing is very important.

The Ideal Time Frame

While most folks might choose to seed their lawns in the spring, which is perfectly fine for states like Minnesota that have cooler temperatures year-round, early fall might be a better time to plant.

According to the University of Minnesota, you’ll want to plant your grass seed between mid-August and mid-September. The logic behind this strategy is that you’ll avoid potentially highly high temperatures during the summer months, which can hurt germination. And since nights in Minnesota are typically cooler and longer in early fall, this will assist your grass in retaining more moisture without drying out.

Conditions for Planting Grass Seed in Minnesota

Ideal Temperature

One thing to keep in mind when thinking about the temperature in relation to grass seed is that you don’t want to go by the atmospheric temperature but rather your soil temperature. After all, your soil is where your seeds will grow, and the temperature variations between the atmosphere and soil can be quite significant.

Since the best time to plant grass seed in Minnesota is in the early fall, you’ll need to plant cool-season grass varieties. These green grass seeds thrive in daytime atmospheric temperatures ranging from 60 to 70 degrees Fahrenheit.

At this atmospheric range, your soil should range between 50 and 65 degrees Fahrenheit, which are the ideal soil temperatures for grass seed germination.

Garden Specialist with Rake Preparing Soil For Natural Grass during the Best Time to Plant Grass Seed in Minnesota

Preparing the Soil

As is the case with any garden bed, you want to try and improve the condition of your soil as best you can before planting your grass seed. This is especially important if you’re working with heavy clay or compacted soils.

If you’re soil’s compacted, it will need to be loosened using either a spade for small batches or a tiller for an entire bed.

If your soil is poor, such as clay or sand, spreading a few inches of compost and Mixing it in will help the clay soil drain better and help sandy soil retain more nutrients and moisture. Doing this also adds beneficial nutrients and microbes.

Best Method

This method applies for starting with soil, not previously grown grass.

For small batches, you can sow the grass seed by hand, but using a handheld spreader will ensure more even distribution.

For larger areas, you can use a drop spreader which will deposit the seeds beneath it. Or you can use a broadcast spreader, which will fan the seed out in a circular pattern.

Once you’ve spread your grass seed, take a garden rake and lightly work the seed into your soil no more than one-quarter inch deep.

If you are sowing your entire lawn, you may want to think about renting a lawn roller. This device will flatten your soil which can provide closer seed-to-soil contact.

Finally, add your mulch which can be a biodegradable material such as straw or seed starter comprised of paper. You’ll also need an adhering agent along with some seed-starting fertilizer.

By mulching, you’re helping to discourage local birds from eating up all your hard work while ensuring your seeds have more moisture for germination.

Man seeding and fertilizing residential backyard lawn with manual grass seed spreader.

Water Requirement

If you’re using mulch, then you’ll want to water daily in the morning. However, if you’re not using mulch, then you’ll need to lightly water two to three times per day. The main trick is to keep your seeds moist but never soggy — which is a fairly universal rule for most plants.

When to Overseed Lawns in Minnesota

Overseeding is a simple concept that involves laying out seeds over your existing lawn. Doing so can help perk up your lawn when it’s beginning to look a bit thin. The best time to overseed is similar to the best time to plant grass seed in Minnesota, which is in the early fall.

Why Should You Overseed Your Lawn?

When you overseed your lawn in early fall, this will ensure your grass root system is stronger as it heads into those colder winter months. And when spring comes rolling around, your lawn will “spring” back looking stronger than ever. Overseeding in the fall will give you a thicker lawn while increasing resistance to drought and reducing weeds that tend to pop up in the spring season.

Planting Grass Seed in the Late Fall in Minnesota

If you need to plant your seed later in the fall, just before winter, this would be the time to dormant seed. Dormant seeding basically the same as overseeding, except it’s best done between late October and early December.

When your soil’s temperature measures below 50 degrees, your grass seeds will stop germinating. This means the seed that’s put down in these temperatures will remain dormant until the snow melts and ground temperatures rise in the spring.

Planting Grass Seed in the Spring in Minnesota

While seeding in the spring can have its benefits, such as increased regular rainfall, there are also a few drawbacks. For instance, thunderstorms may wash away grass seed that is freshly sown. This is especially true if planting seeds on a slope.

Plus, seeding in the spring invites more weeds to grow alongside your grass seedlings.

Grass regenerate in the garden.

Wrapping Up The Best Time to Plant Grass Seed in Minnesota

The best time to plant grass seed in Minnesota will be during the early fall. However, an established lawn can benefit from overseeding or dormant seeding in late fall. Remembering to take factors such as soil temperature is also essential, as well as ensuring your soil’s adequately prepared for your grass seed. Remember to water daily, and your lawn should look fresh, green, and healthy in the spring season.

For more lawn and yard care information along with some Minnesota gardening tips, check out: