Published in the ECHO Journal, September 2013
Indian Summer is here! With warm weather comes the delicate balance of maintaining a beautiful landscape, while still conserving water. One negative side effect that can surface from intense heat is “hot spots” in the turf. “Hot spots” or “brown spots” in turf can occur in warm months and can cause an unsightly curb appeal. Learn what to look for and how to address this issue below.
One of the most common problems in turf care is addressing “hot spots” in turf. Often identified as an area where the turf is not an even green, these “spots” can be easier to see than to know how to fix. Too often, the water is dialed up at the controller and the cost impacts the customer’s pocketbook. There are several steps one can take to help identify the underlying cause, correct the situation, and even help reduce water waste.
One of the most common causes for a hot spot is improper irrigation coverage. Coverage issues can include clogged or misaligned nozzles, tilted or blocked heads (by turf or plants), and poor operating pressure of the irrigation station. A very common solution often overlooked is to watch the station and see if the heads are all functioning normally. Use of a pressure gauge at the heads will help determine if the heads are operating at the manufacturer’s recommended pressure. Too many heads, a broken head or lateral, and flow restriction at the valve all can affect sprinkler performance. Low pressure on rotors creates a “donut” ring around the head. If heads and nozzles are correct, but heads still lack “head to head” coverage, consider adding a head, where needed (if system capacity is adequate, or upgrade to rotary nozzles. Too much flow may require splitting the station up into more than one valve.
Another common cause for a hot spot can be actually due to a grassy weed, known as “Poa Annua”. This weed looks like grass, but has a very shallow root system; then during the summer, when the real grass deeper roots, these areas are starving for more frequent watering. Since soil evaporates more quickly at the surface, these weeds will show signs of stress. A careful strategic plan in the early spring to “slit seed” the turf area with hardier grasses that will help crowd out the weeds and help save water in the summer heat.
One of the last recommendations for addressing a hot spot is to check the soils. This can be done initially with a soil core tool. Look at samples throughout the turf station, both in green areas and in the hot spots. If the soils are healthy, the soil shouldn’t have a rotted smell, and root depth should be at 4-6 inches. The turf station should have consistent moisture content throughout. If these are both okay, then the issue may be with the soil itself. There may be damage due to fertilizer burn, plant disease, or bad soil microbes. Consider sending soil samples from both good and bad to a lab for analysis.
Judy O’Shaughnessy is the marketing manager at Cagwin & Dorward Landscaping Landscape Contractors. She is the secretary of the Maintenance Resource Panel.