Canadian peat moss is all you need to stop, reverse grass root rot

There aren’t many new turf insect and disease problems from year to year. When one does appear, it’s fairly newsworthy.

Now, we have take-all root rot (take-all patch) in North Texas lawns.

Texas’ resident expert in this disease is Dr. Phil Colbaugh, the recently retired and highly respected plant pathologist of the Texas Agricultural Experiment Station of Texas A&M. Dr. Colbaugh conducted exhaustive research (and continues to) on the disease and how best to deal with it.

Identifying take-all patch is challenging. Since most of us saw it initially in St. Augustine, I’ll use that as my example. The grass thins and dies away, much as it does when there isn’t enough direct sunlight. It shows iron deficiency, and it’s very lethargic. Feeding it doesn’t help. When you pull on the grass, it comes loose from the soil very easily.

Most of us who have encountered take-all patch didn’t recognize it for some time after the grass started to decline. We tried fertilizer, and then fungicides. We even tried planting new grass, but the problem only got worse. Most of us were growing St. Augustine, but we began to hear about similar issues with bermuda lawns, particularly hybrid bermudas.

That was about when Dr. Colbaugh’s first news releases started to emerge — probably eight or 10 years ago. His initial research suggested that fungicides were not the answer to this insidious disease but that spreading a layer of organic matter across the entire lawn would turn things around.

Jump ahead another year or two, and Dr. Colbaugh was recommending a specific type of organic matter — any brand of Canadian peat moss — as the only control you would need. It wasn’t a ploy to get us to buy peat moss, but instead, a scientist’s faithful reporting of what he had discovered.

Colbaugh was right. When we spread a pulverized one-inch layer of Canadian peat across our lawn, then raked and watered it into contact with the soil, the disease abated and the grass started to regain its vigor and looks almost overnight. Within weeks, it started to grow vigorously and fill in the voids.

Your biggest problem in applying peat moss to your lawn will be in bursting the blocks of compressed peat moss open, then distributing the peat uniformly across the turf. Use a garden rake turned upside-down to smooth the peat, then use a water breaker to wet the peat and wash it into contact with the soil.

Within a few days the peat will have settled in place and formed the acidic layer on the soil’s surface. Take-all root rot isn’t active in an acidic environment.

Will you need to repeat the application of peat moss? Yes, according to Dr. Colbaugh. He says it may give relief for up to three years, but some lawns have benefited from annual applications as the grass is greening each spring.

If you have turfgrass that is struggling in spite of your great care and attention, consider that it might have take-all root rot. You can confirm its presence by sending tissue samples to Texas A&M’s Plant Disease Diagnostic Laboratory. Or, probably for less money, you could buy a couple of bales of peat and spread it over a test portion of your turf. Odds are, the results will be stunning, and that alone will give you your answer.