Author: Dianne DeLongchamps
Why does my dog’s urine leave dead spots in my lawn?
Dog urine leaves dead spots because a large amount lands in one small area. CSU Extension says the nitrogen-containing compounds and salts in that concentrated deposit can injure or kill the grass. Water is the only product CSU says reverses the effects, and training your dog to use a non-turf area is the only sure way to stop new spots.
Clean Air Lawn Care treats lawns in Fort Collins, Windsor, and Timnath. The majority of the lawns we maintain in Northern Colorado are turf-type tall fescue or Kentucky bluegrass, so the repair steps below start with those two grass types.
Dog urine damage has sparked many home remedies and commercial products, and CSU says the causes and solutions are often misunderstood. Here is what CSU Extension’s research-based guidance says works and what it says does not.
What the spots look like
PlantTalk Colorado describes straw-colored grass, or dead spots with dark green borders, as common in lawns where dogs are present. Not every spot turns brown. CSU’s Garden Notes fact sheet says that some spots stay green because the urine stimulates growth, and those dark green spots are especially visible on lawns that are not getting enough nitrogen fertilizer.
Four myths about dog spots
Myth: only female dogs cause spots. CSU calls this false. Spotting is most often caused by dogs that squat when they urinate, which puts a large volume of concentrated urine in a small area. Most squatters are female, but some males squat too, especially in their own yard. Many male dogs mark vertical objects such as trees and posts instead, which causes problems for some landscape plants.
Myth: certain breeds cause more spots. CSU rates this as mostly false. Larger dogs make larger amounts of urine, so their spots are more likely or more obvious. Small dogs can cause spots too, especially if they use one limited part of the lawn.
Myth: a supplement that acidifies urine prevents spots. CSU calls this false. Dog spots do not occur because urine is alkaline, and CSU states that no dietary supplement has been scientifically proven to reduce how often or how badly dogs spot a lawn. Products sold to make urine less alkaline may cause urinary system problems and can affect how calcium is deposited in the growing bones of younger dogs. CSU says to call a veterinarian before giving a dog anything that changes urine pH.
Myth: baking soda, gypsum, or dish soap neutralizes the spot. CSU calls this false as well. Baking soda and gypsum are salts and may add to the problem, and some dishwashing detergents can burn grass. PlantTalk Colorado adds that products claiming to dissolve or leach the salts have not proven effective. CSU also says no spray-on product sold for dog spots has been scientifically proven to prevent or cure them.
What actually stops new spots
CSU’s Garden Notes says to train the dog to use a non-turf area, such as a spot covered with mulch or gravel, or to pick a place where spotting will not be an eyesore and the damage can be tolerated. It calls this the only sure solution. PlantTalk suggests an unplanted area, a graveled area, or a corner of the property set aside for the dog.
Water helps from two directions. CSU says to always provide adequate water for your pet, because a dog that drinks more makes more dilute urine, which lowers the chance of turf injury. PlantTalk notes that following the dog around and rinsing each spot with a garden hose dilutes the urine on the lawn side, although it takes a lot of labor.
Before adding salt, garlic, tomato juice, or any other home remedy to your dog’s food, talk to your veterinarian. CSU says extra salt can cause problems for older dogs and for dogs with heart or kidney conditions, and it says no additive or supplement other than water should go into a dog’s food without a veterinarian’s approval.
How to repair a spot that has already turned brown
For brown spots, CSU says to water more often or for longer. That dilutes the salts that have built up in the soil, helps living grass recover, and makes reseeding work better where the grass has died. PlantTalk says to soak damaged spots with a hose for a few days before reseeding or resodding.
If the grass is dead, CSU says you can remove the dead sod along with 0.5 to 1 inch of soil and lay new sod. You can also reseed individual spots, but the seed has to match your lawn:
- Kentucky bluegrass lawn: Use Kentucky bluegrass (marginally effective) or perennial ryegrass (more effective). Do not use tall fescue, K31 tall fescue, dwarf fescue, or annual (Italian) ryegrass.
- Tall fescue lawn: Use turf-type tall fescue, which is sometimes called dwarf fescue. Perennial ryegrass also works, but its finer texture means the patch will look different. Do not use K31 fescue or annual ryegrass.
- Fine fescue lawn: Use fine fescue seed. CSU does not recommend perennial ryegrass or tall fescue there, because the spots will differ in color, texture, and growth rate.
- Zoysia or bermudagrass lawn: Patch with sod from a sod farm, or with sod taken from an inconspicuous part of the same lawn.
If your lawn has brown spots and you are not sure what is causing them, we’re happy to take a look.
Clean Air Lawn Care Northern Colorado is owned by Dianne, Paul, and Luke DeLongchamps — a family business serving Fort Collins, Windsor, and Timnath with organic lawn treatments and solar-powered electric equipment.
