I first heard about Dog Rocks in a Facebook Group a couple of weeks ago. Someone was looking for a solution to the urine burn marks their dog left on the lawn and Dog Rocks were suggested. At first I visualized rocks that were used to cover up the burn marks, but that is not how this product works. Instead you put the rocks in the drinking water and they absorb nitrates from the water. As one advertisement put it, “less nitrates going in means less nitrates coming out the other end,” With lower nitrates, the grass is not burned and your dog no longer creates spots on the lawn.
Normally, when I review products for the garden I try to be politically correct and bite my tongue, but not this time. This is the dumbest product I have ever come across. A small bit of logic will tell you that it has zero chance of working and I’ll explain why shortly.
Why Does Dog Urine Burn the Lawn?
The first cause that comes to mind is pH. What is the pH of dog urine? The normal pH for dog urine is around 6 to 6.5, which is the ideal pH for growing most plants. So clearly it is not pH.
The next suspect is nitrogen. We all know that if we spread too much fertilizer on lawn grass, it burns. The culprit in this fertilizer is nitrogen. Too much nitrate or ammonium will kill plants.
Urine contains fairly high levels of urea, which is quickly converted to ammonium when exposed to water and then to nitrate through the action of bacteria.
Dogs burn lawns because of high levels of urea.
How Do Dog Rocks Work?
The promoters of this product explain it this way, “Dog Rocks are a paramagnetic igneous rock which create a magnetic field within the water causing a change in the ion exchange. This in turn diminishes the nitrates that are found in the water.” They claim that the rocks absorb nitrate from the water, which results in less nitrate being urinated on the lawn.
As soon as you see “paramagnetic” anything, it’s a red flag for false advertising. I can’t think of a consumer product where paramagnetism provides any benefit.
No scientific studies are available from the manufacturer to prove any of this, which is surprising since “The product was researched for 4 years and then went on the market.” It would only take a few days to put some rocks in water and measure the decrease in nitrates. This would not prove they work but at least it would prove their theory is plausible.
Interestingly, they do post a report from McGill, Office of Science and Society, which discusses why dog urine has high levels of nitrogen, but this report does not mention Dog Rocks, nor does it put any of the blame for high nitrogen in urine on the water that dogs drink.
Video on Dog Rocks
Is Nitrate in Drinking Water a Problem?
Most people use home tap water to water their lawn. This is the same water that is used to fill the dog’s water dish.
Why is it that when you water your lawn with this water you get no grass burn, but when a dog pees on the lawn after drinking the same water, you get a burn? Clearly, the nitrates in drinking water are not burning the lawn!
It is quite obvious to me, that the high levels of urea are not from the drinking water, but from the rest of the dogs diet and the report by McGill confirms this. A high meat diet contains a lot of protein, which contains high levels of nitrogen. This results in higher urea levels in the urine.
Nitrogen levels in drinking water are not the problem. So even if the Dog Rocks did as claimed, they would not reduce damage to the lawn.
Do Dog Rocks Remove Nitrate From Drinking Water?
There is no science to support this idea, and the company promoting the product has no data to support there claim. The scientific mumbo jumbo they use to explain their product makes no sense.
It is unlikely that these rocks reduce the level of nitrate in water but if they do, it would be insignificant.
Solving Lawn Spots
There are four things you can do to stop damage to your lawn from dog urine.
- Reduce the meat in the diet. This reduces urea in the urine.
- Water the lawn right away after a dog pees. This dilutes the nitrogen level and washes it lower into the soil, making your grass grow better.
- Train the dog to pee in the same spot all of the time.
- Get a cat!