The nitrogen from dog urine releases quickly, while the nitrogen from dog droppings releases slowly. This sounds like fertilizer we would happily use on our lawns and in our gardens.
Contrary to what some people would like to believe, dog waste does not fertilize lawns, gardens or trees. It is a misconception, if not a fabrication, that dog excrement is a non-issue in our environment. Dog urine and feces damage plants, burn lawns, attract flies, stink and carry disease.
We all know that composted manure is better than chemical fertilizer because it contains organic matter that builds our soil as it feeds our plants. However, it is important to note that good manure comes from herbivores like chickens, horses, cattle, goats, sheep and rabbits. It is unwise to use composted manure from dogs, cats or any other meat-eating animals because it carries the risk of transmitting parasites and disease-causing organisms. The backyard compost made by homeowners does not kill all parasites and pathogens.
Dog feces spread adenovirus, parvovirus, giardia, coccidian, roundworm and tapeworm, E. coli, fecal coliform bacteria, salmonella and more. These pathogens and parasites are harmful to not just human beings but other dogs and wild animals as well.
Notably, children play on the ground, and then touch their hands to their mouths and eyes without washing their hands. The eggs of roundworms, hookworms and other parasites can live in soil for a number of years. This is a pet waste management concern.
Dog feces, in particular, are an environmental concern. Heavy rainstorms carry dog droppings into waterways and down storm drains. The excrement contributes to algal blooms in our ponds and high bacteria levels in areas where we swim and boat. When left on the ground it ends up in the water table.
The environmentally acceptable thing for dog owners to do is to pick up after their pets and take the waste home to an in ground (if the water table allows) backyard doggie waste composter or flush it. Flushable pet waste bags are available commercially.
There is an abundance of nitrogen in both dog feces and urine. When left on the lawn feces release nitrogen which, in time, burns the grass and results in damaged brown patches of lawn. Feces break down slowly, but at least can be picked up and removed from a lawn or garden.
Dog urine is a different problem. It can’t be removed. Urine is a concentrated liquid that burns plant material straightaway and then soaks into the soil. It is harmful in concentrated amounts.
Damage to lawns from dog urine manifests as burned brown spots surrounded by a halo of bright green grass. Female dogs typically expel all or most of their urine when they squat. That produces an overload of nitrogen which damages or kills the grass in small areas. The green halo around the fertilizer burn develops because the periphery is fertilized rather than damaged by the surplus of nitrogen.
Males mark trees and shrubs with smaller amounts of urine; but repeated marking with small amounts of urine is damaging and sometimes lethal to small plants, shrubs and young trees, especially when an individual plant becomes a marking post for all the neighborhood dogs.
Water dilutes the nitrogen and salts left behind from dog urine. It is ameliorative to spray affected areas and plants with water to reduce the mineral residue.
Constant urination on a patch of ground results in the buildup of salts. Eventually plants will be unable to grow in the affected soil. If that happens the best course of action is to dig out the surface soil and replace it with compost to restore soil health. Spots may be numerous, but at least they are small.
The Environmental Protection Agency has designated pet waste a “nonpoint source pollutant,” along with herbicides and insecticides. As gardeners we are stewards of our environment. Management of pet waste is within our purvue, especially as it affects our lawns and gardens.
Reach DEBBIE MENCHEK, a Clemson Master Gardener, at firstname.lastname@example.org.