CML Idiot’s Lawn Guide: Chapter 5 – Out, damn spots!

Well, it’s July and Cranky’s front lawn is showing signs that summer’s heat is taking its toll!  It’s an inevitable annual development.  No matter how much rain we get in April, May, June, it’s never enough to get the home turf through the summer unscathed.  And besides the heat, there are other dangers afoot …

Brown spots in your lawn can be caused by any number of things.  At this time of the year the culprits are innocuous occurrences that are simply magnified by the sun and heat.  For instance, I have noticed a good deal of spotting along the sidewalk in front of Cranky Man’s palatial estate.  At first I ran through the more dangerous threats, like over-fertilizing and grub damage; but after reviewing the overall condition of the East Lawn, I was able to eliminate both potential causes. 

There were three keys to my conclusion with a Confidence Factor of 90%:

  1. Spotting on the rest of the lawn was minimal (some from high-activity landscaping/gardening near the East Garden that fronts the East Lawn);
  2. There was scant evidence of grub-type insects in the soil and grass; and
  3. I caught the big golden retriever from down the block peeing along the spotted section of grass!

Often it’s the simplest explanation that causes discoloring to a lawn.  That’s why it’s important to look at the overall condition of your lawn before drawing conclusions about what the problem is and what the treatment should be. 

 The first conclusion MOST lawn overseers will make to brown spots at this time of year is grub infestation.  Late June – early July (Southeast Pennsylvania) is normally when you will begin to see the insects that develop from the white grubs that have the greatest potential to do damage to your lawn.  But that damage will actually be evident as early as April, when white grubs roust from their winter slumber to feed and mature into beetles (i.e. Those brown spots will appear well before the insects appear.)

In my case, it was dogs not slugs that were responsible for the brown spots.  As a dog owner, I can appreciate and make allowances for doggies doing a #1 on the lawn (just don’t leave its #2 lying about, please).  That kind of damage you can live tolerate, since its not permanent or pervasive.

And since grub treatments tend to be the MOST EXPENSIVE of traditional lawn treatments available at your local lawn supply store, it’s best not to jump to the conclusion that grubs are a threat to your lawn.  It’s important to know thy enemy! 

Personally, I haven’t applied a grub treatment for several seasons now, due to the relative scarcity of Japanese beetles (white grub=larvae stage) in late June-early July.  As has been the constant theme at Cranky Man’s Lawn, common sense, education and observation are important keys to sensible lawn care. 

Here are several good websites that will help you learn how to recognize, evaluate and treat a grub infestation:

Penn State University, College of Agricultural Sciences – PSU is a leading authority on turf management.

New York State Integrated Pest Management Program – Out of Cornell University   

University of Illinois – Pegged to lawn conditions in Northern Illinois, but good info!

Cranky Man’s twist on the above information, carefully fine-tuned from years of haphazard observation and other serendipitous methodologies:

  • NEVER use Japanese beetle traps during the height of an infestation.  I made this mistake a few years ago, until I realized these pheromone-baited traps (Some use a floral lure.) attracted THOUSANDS of randy beetles from MILES around (or so it seemed).  And since only a percentage of the attracted beetles actually get caught in the trap, you may just turn your lawn into a Best-Of-Beetle dating site, nursery and smorgasbord!
  • Small numbers of beetle larvae (See the PSU and Illini site for how to “survey” your lawn for unwanted guests.) are not a threat to overall lawn health.  Finding a dozen grubs in one square foot of lawn would indicate a significant pest problem.  If it’s less than that, you MAY NOT have a grub problem!
  • Look for damage from moles, raccoons, and skunks, or a number of birds doing a high level of foraging in your lawn.  They LOVE grubs.  If they like your lawn, chances are the grubs are there enjoying your lawn too!      

What to do about those ugly brown spots once either the heat, the dogs, or the grubs have done their dirty work:

  • Don’t overreact and rip up the brown grass.  No lawn grows much in the heat of summer.  Minimize the damage and protect the roots by leaving the unsightly – but useful – brown grass in place. 
  • Make sure you KNOW what the problem is before you treat it!  You can do MORE DAMAGE to your lawn applying fertilizer to a hot, dry lawn!
  • Wait until early to mid September, then remove the brown grass and spread seed and fertilizer over the affected area.  (This is always a good time to over-seed and fertilize your entire lawn.  More on that in a later posting.)  With good weather, you could easily get 6-8 weeks of autumn growth to give you a head start on Spring!  
  • Remember that it’s the  lawn’s overall health that’s MOST important.  Few lawns are free of bad spots, so temper your expectations during the hot summer.  Understand the problem; minimize the damage; repair it when conditions for growth are most favorable!

Good luck!

2 thoughts on “CML Idiot’s Lawn Guide: Chapter 5 – Out, damn spots!

  1. I just raked out the brown area in my lawn. It is basically this thin, wispy grass somebody planted before I lived here. I was told by a past neighbor that a tree had been planted in the same area that goes brown early every summer. So I rake out the matted dead grass. I am seriously considering power thatching or power raking the entire lawn, I read somewhere that thatching should be done annually in July, the most prolific growing period for turf.

    It seems that after raking the area out the grass that remains greens up a bit.


    • Around here you do not depend on anything growing in July. Power thatching will remove much of that dead, brown undergrowth. In this area, September is the best time for that, as the late summer/early fall weather gives us a later growing season.


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