If you live in a colder climate like Southwest Montana, you’ve probably noticed your lawn turning yellow or brown as winter approaches. That’s not your lawn dying, it’s going dormant. Here’s what lawn dormancy actually is, what your grass is doing during this time, and how you can support a healthy comeback in spring.

What Is Lawn Dormancy?
Dormancy is a natural survival process your lawn goes through during cold winter months. In our region, lawns typically enter dormancy around November and begin waking back up in late March or April, depending on weather conditions.

During dormancy, grass conserves energy to protect itself from freezing temperatures. With proper care, your lawn will rebound when spring arrives.

What Happens When Your Lawn Goes Dormant?
In the fall, your lawn shifts its focus below ground. Instead of sending energy to the grass blades, it moves nutrients and energy into the root system. This is what causes the yellowing or browning you see above ground.

While the lawn stops growing on the surface, the roots remain active throughout winter. They store nutrients that the lawn will rely on during its “hibernation” and early spring green up.

What Happens When Your Lawn Comes Out of Dormancy?
As temperatures warm and snow begins to melt, your lawn uses any leftover stored nutrients, sunlight, and moisture to transition back to active growth. This is when your grass starts greening up and filling in again.

If your lawn went into dormancy healthy and well fertilized, then it will come out of dormancy much quicker in the spring.

Treatments That Support Healthy Dormancy
At Yard Guard, we strongly encourage both the first and last lawn applications of the year. These treatments deliver a high load of nutrients right when your lawn needs them most, before going dormant and as it wakes back up.

With our Blended Organic program, those nutrients are focused on soil health, restoring the microorganisms and creating a healthier environment that supports long term lawn health.

How to Care for a Dormant Lawn
Dormant lawns are more fragile than they look so we recommend protecting them as much as you can:

• Limit foot traffic: Frozen grass blades are prone to breakage, which can damage the lawn and increase compaction.
  
• Spread out snow piles: Large, concentrated piles take longer to melt and can contribute to snow mold* in spring.
• Use salt sparingly: Excess salt from driveways and sidewalks can damage grass and soil as snow melts.

*Snow mold forms when excessive moisture from snow piles stays in one area. It usually appears as gray or pink mold in early spring. While it looks unsightly and can slightly slow growth, it does not permanently damage your lawn and typically resolves on its own.

The Bottom Line
During dormancy, your lawn is resting, protecting itself, and storing energy for spring. With the right fall treatments, an early spring treatment and mindful winter care, your lawn will be well ready to come out of dormancy healthy, green, and strong.

I bet you’re excited to stop mowing soon, but please don’t put those mowers away just yet. We have a couple fall mowing recommendations that will help set your lawn up for success next spring and summer.

Your lawn is just starting to thrive again after struggling through the heat of the summer. The cool nights and shorter days are allowing it to go through another growing cycle before going dormant in the next couple of months. This is the most important time of year for all plants – they are sending energy down to their roots as storage for next year. Even though you don’t see a ton of top growth, plants (including lawns) are really active late into fall.
Side note: this is why it’s so important to get a fall fertilization before the lawn goes dormant, it needs the nutrients while it’s pushing growth and to overwinter well. 

We recommend continuing to mow your lawn as normal: once a week, ensuring the height is at 3.5-4” until it starts to go dormant. Once it’s fully dormant, lower your mower to 2 inches and bag the clippings. This final cut helps reduce the risk of snow mold and eliminates habitat for voles, while still providing enough protection for your soil and roots through winter.

When your lawn goes dormant truly depends on the time of year (mostly soil temperature) and how much moisture the lawn is getting, but typically you’re going to be looking at the end of October/beginning of November for lawns in the Gallatin and Park counties. A good rule of thumb: after the first snow that melts away, it’s time for that last mow of the season.

P.S.: Please be sure to remove the leaves that are on your lawn. As a rule of thumb 20% coverage of the lawn is fine, anything over that could create disease issues in the coming year. Read more about that specific topic here: To Rake or Not to Rake.

To summarize our fall mowing recommendations: 

• Mow your lawn as normal until it starts to go dormant. 3.5-4” height is preferred
• Once fully dormant, lower the mower to 2” and bag the clippings to reduce vole habitat and risk of disease in the future year. (around Halloween)
• Pick up at least 70% of the leaves on your lawn. 
• DON’T skip your last fertilization app!

Now that spring has sprung and everything is beginning to bloom, we hope you were able to get in one good close cut to rid your lawn of its dormant brown blades. If not, it’s not too late to start a regular mowing schedule to get you grass in tip top shape this season. 

As you prepare for greatness, there are three things that we want you to keep in mind for each mowing session: keep your deck high, more frequent cuts, and sharp blades. Focusing on these three things, along with a great watering schedule and the added bonus of our lawn care services, will be all you need this season to keep your lawn vibrant and green as it continues to grow. 

Keep your mower deck high
Leaving your grass to grow too long can create a breeding ground for pests as well as fungal issues caused by a lack of air circulation in densely packed grass. On the other hand, cutting grass too short leaves it vulnerable to weed infestation, drought, and diseases. Removing more than ⅓ of the height of a blade of grass at one time not only stresses the grass, but it also leaves the grass with too little surface area for it to photosynthesize. This is known as the “one-third rule,” and in order to make sure you only cut ⅓ or less of your grass blade each time, your deck needs to be set high. Depending on the type of mower you have, your deck should be set to a height that will keep your grass blades between 3 ½  to 4 inches high after trimming. This is the generally accepted height range for grass that is neither too short nor too long.    

More Frequent Cuts
Spring is the peak growing season for your lawn, so it grows back just as fast as you cut it. This alone makes more frequent cuts a necessity, but it also goes hand in hand with keeping your deck high. We know, we know. With busy work schedules and balancing every other responsibility that you have, cutting the grass more often was probably the last thing you wanted to hear. But, there’s no way around this one. If you want to maintain grass that has a healthy root system, you must cut small amounts at a time and do so more often. This is important for the one-third rule that we just talked about, as well as the fact that the roots of a blade of grass mimic the leaf that is above ground. We want to encourage a thriving root system, and this can be done by cutting your lawn more often so that you’re creating a consistent mowing height which reduces stress on the grass as well.  A cool side effect of this, is the fact that these smaller clippings also decompose quicker and provide nutrients to the lawn that act as a natural fertilizer to your grass. Trimming your lawn 1-2 times per week should do the trick. As we progress into summer, this schedule will become much less frequent, and the cooler days and nights in the fall will start to push more growth for these cool-season Montana grasses. 

Sharp blades
The sharper the blades, the cleaner the cut! Plain and simple. If your blades are dull or they haven’t been replaced in a while, this may be the reason why your grass is yellow. Dull blades rip and tear at your grass instead of clipping it neatly and evenly. These ragged edges are now susceptible to disease and dehydration. Make sure your blades are up to par before every mowing session to prevent these tears and the yellowing that is sure to follow.

Now that you have these tips in your back pocket, the next steps would be to add in a consistent watering schedule and supplement with nutrients from one of our programs. Reach out to us to see what else you could be doing to get your lawn a cut above the rest.