The Bay Gardener by Dr. Frank Gouin
Is Your Landscape Going to the Dogs?
Tips for dog-loving gardeners
As lovable and as faithful as dogs can be, many have been known to raise havoc with landscapes. Brown patches on lawns are most commonly caused by female dog urine. Brown branches on boxwoods, privet and yews six to 18 inches above the ground are most often caused by the urine of male dogs. Smooth-bark trees such as young dogwoods, maples, oaks, linden, ash and pine can sometimes be harmed from male dogs frequently urinating on the same place daily, especially during periods of drought.
The brown patches in the lawn and on branches are caused by the combination of salt and ammonia contained in the urine. The injury on the lawn is more pronounced during drought than during periods of frequent rains. The rains dilute the urine, cool the soil and wash the salts and ammonia deeper into the soil.
The problem can be lessened by sprinkling a gallon of water directly over the grass immediately after the urine has been deposited or by washing off the foliage of the shrubs and the tree trunks with water. There is some indication that lawns that are built on soils with five percent or more organic matter tend to be more resistant to dog urine damage than are soils with little to no organic matter. It would be interesting to research whether top-dressing lawns with compost reduces dog urine damage.
During the dog days of summer, many dogs dig themselves depressions in shaded areas in an attempt to stay cool. Most dogs will repeatedly go back to the same spot and scrape away some soil before lying down. Shallow-rooted species such as azaleas, rhododendrons and mountain laurel can be severely damaged and even killed by such digging.
In these situations, I encourage owners to replace the plants with species that are deeply rooted such as viburnum, cotoneaster or forsythia. If this is not possible, I recommend hanging a canister of mothballs in the shrub. Most animals do not like the smell of mothballs and they are not easily washed away by rains as are commercially available products such as Dog-Off, Dog Be-Gone or Dog-Away.
Do not add the stools of dogs to compost piles if the compost will be used in the vegetable garden. There is always the possibility that the stool may contain round or hook worms. To kill these organisms, it would be necessary to raise temperature in the compost pile to 150 degrees for at least five consecutive days. Such high temperatures are normal in commercial composting facilities but almost impossible in most home composting systems.