Why Colorado Lawns Turn Brown in Summer

Few things frustrate homeowners more than watching a lawn turn brown during the hottest part of summer, especially after spending time and money watering, mowing, and maintaining it.

The good news is that brown grass does not always mean dead grass. In Colorado, summer heat, drought conditions, irrigation issues, and lawn stress can all cause grass to temporarily discolor.

At Mile High Grass Cuts, we help homeowners identify what’s causing lawn problems and how to prevent long-term damage during Colorado’s intense summer months.

If your lawn is turning brown this summer, here are the most common causes and what you can do about them.


1. Summer Dormancy

One of the most common reasons for brown grass in Colorado is dormancy.

What is lawn dormancy?

Dormancy is a natural survival response. During extreme heat or drought, grass may temporarily slow growth and turn brown to conserve energy and moisture.

This is especially common with cool-season grasses like:

  • Kentucky Bluegrass

  • Tall Fescue

Dormant grass is often still alive underneath the surface.

Dead Grass vs Dormant Grass

Many homeowners panic when their lawn browns, but there’s a difference between dead grass and dormant grass.

Dormant grass:

  • Often appears light brown or tan

  • Usually recovers when temperatures cool or watering improves

  • Grass blades may still have some flexibility

Dead grass:

  • Pulls out easily from the soil

  • Feels brittle and dry

  • Does not recover after watering

Colorado lawns commonly go partially dormant during prolonged summer heat waves.

2. Underwatering

Colorado’s dry climate causes moisture to evaporate quickly, especially during July and August.

Signs of underwatering:

  • Dry or crunchy grass

  • Footprints remaining visible

  • Bluish-gray tint

  • Brown patches forming in sunny areas

Shallow watering is another major issue. Watering lightly every day often creates weak, shallow roots that struggle in hot weather.

What works better:

  • Deep watering

  • Fewer watering days

  • Early morning irrigation

Most Colorado lawns perform best with deep watering 2–4 times per week depending on weather and soil conditions.

3. Overwatering

Surprisingly, too much water can also turn lawns brown.

Signs of overwatering:

  • Mushrooms

  • Soggy soil

  • Yellowing patches

  • Fungus growth

  • Shallow roots

Overwatering prevents roots from growing deeper into the soil and can create ideal conditions for lawn disease.

Colorado lawns need balance — not constant saturation.

4. Heat Stress

Even properly watered lawns can become stressed during extreme Colorado heat.

High temperatures combined with intense sunlight, low humidity, hot pavement reflection & dry winds can quickly stress grass.

Signs of heat stress:

  • Brown or faded areas

  • Wilted appearance

  • Slow growth

  • Thin grass coverage

How to Prevent Heat Stress

Raise mowing height

Taller grass helps shade soil and retain moisture.

Avoid mowing during peak heat

Mowing in the afternoon heat can increase lawn stress.

Water deeply

Deep roots help lawns survive hot weather more effectively.

Keep mower blades sharp

Dull blades tear grass and increase moisture loss.

Summer lawn care in Denver and throughout Colorado is largely about helping grass survive environmental stress.

5. Mowing Grass Too Short

Scalping the lawn is one of the fastest ways to damage grass during summer.

Short grass:

  • Dries out faster

  • Exposes soil to heat

  • Weakens root systems

  • Encourages weeds

  • Increases browning

Recommended summer mowing height:

Most Colorado lawns should stay around 3 to 4 inches tall during summer. Longer grass provides natural protection against heat and drought.

6. Fungus & Lawn Disease

Some brown patches are caused by fungal problems rather than watering issues.

Common causes:

  • Overwatering

  • Poor drainage

  • Watering at night

  • Excess moisture sitting on grass

Possible signs of fungus:

  • Circular brown patches

  • Slimy or wet areas

  • Mushrooms

  • Discolored rings

Colorado lawns are generally less humid than many states, but fungus can still appear during periods of excessive watering or summer storms.

7. Dog Spots

Pet urine spots become much more noticeable during hot weather.

Common appearance:

  • Small brown or yellow circles

  • Dark green ring around the edge

The combination of nitrogen and salts in urine can stress grass, especially when lawns are already struggling with heat.

Ways to reduce dog spots:

  • Water areas after pets use the lawn

  • Keep grass healthy and hydrated

  • Reseed damaged patches when needed

8. Irrigation Problems

Sometimes brown grass is simply caused by uneven sprinkler coverage.

Check for:

  • Broken sprinkler heads

  • Clogged nozzles

  • Dry spots

  • Overspray

  • Poor water pressure

Many lawns have sections that receive too much water while others receive almost none.

Regular irrigation checks can prevent a lot of summer lawn problems.


Final Thoughts

Brown grass in summer does not always mean your lawn is dying. In Colorado, lawns deal with intense heat, drought stress, dry air, and rapid weather changes that can temporarily affect appearance.

The key is identifying the actual cause before overcorrecting with more water or unnecessary treatments.

Healthy mowing habits, proper irrigation, and consistent lawn maintenance go a long way toward preventing summer browning.

If your lawn needs help surviving Colorado’s summer heat, Mile High Grass Cuts provides professional lawn maintenance and seasonal property care to keep your yard looking its best.


Frequently Asked Questions

Why is my lawn turning brown in summer even though I water it?

Heat stress, overwatering, fungus, compacted soil, irrigation problems, or mowing too short can all cause browning.

Will dormant grass come back?

In many cases, yes. Dormant grass often recovers once temperatures cool and watering improves.

How do I know if my grass is dead or dormant?

Dormant grass usually remains rooted and may recover. Dead grass pulls out easily and stays brittle after watering.

Does mowing height affect brown grass?

Absolutely. Grass cut too short dries out faster and becomes more vulnerable to summer stress.

Can overwatering cause brown grass?

Yes. Too much water can lead to shallow roots, fungus, and lawn disease.


Need help keeping your lawn healthy through Colorado’s summer heat? Contact Mile High Grass Cuts for recurring maintenance, weed control, and seasonal lawn services.

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