Good afternoon,

Thank you for contacting the Colorado State University Lawn and Garden Help desk with your question about your lawn.

In order to diagnose your lawn problem, we'll need some photos of your entire lawn area in addition to the closeups of the affected area you provided. Also, please answer the following questions.

1.) What type of grass is this? 

2.) Is it a new lawn? If not new, how old? 

3.) Was the soil prepared prior to sodding or seeding? 

4.) What sort of sun exposure does it get? 

5.) When did you first notice the problem this year? 

6.) How do you water your lawn—a hose or an inground system? Type of sprinkler head—spray or rotor?

7.) How often and for how long do you water your lawn?

8.) What time of day do you water? The best time is between 9pm and 9am.

9.) Have you fertilized? When? With what?

10.) Have you treated with any herbicides, pre-emergent or other?

11.) Have you done any de-thatching recently?

12.) How often do you mow your lawn? Typically, one should not remove more than 1/3 of the grass blade at a time.

13.) What is your mowing height? Based on the latest research, the preferred height for all Colorado species is 2.5 to 4 inches. The higher the better.

14.) Do you leave your grass clippings on the lawn?

15.) Have you had your lawn aerated?

16.) You can try the "screwdriver" test to see how easily a screwdriver can go down in your lawn, if it goes down easily, your lawn is hydrated, if not it may be dehydrated.

In the meantime, here are some resources for lawncare in Colorado: 

Best Practices for Lawn Care: https://engagement.source.colostate.edu/colorado-lawn-care-best-practices/

Best of luck,

Michelle D

Colorado Master Gardener Apprentice