Extreme heat is damaging to lawns

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Our lawns and plants continue to feel the effects of the 104 to106 degree temperatures of June 29-July 1.

Lawns and plants continue to feel the effects of the 104 to106 degree temperatures of June 29-July 1.   SPECIAL
SPECIAL
Lawns and plants continue to feel the effects of the 104 to106 degree temperatures of June 29-July 1.

It didn’t help that we also had days close to or above 100 degrees through the week. Several plants had marginal leaf burn. The azaleas in my front yard bed had plenty of that.

The heat was especially damaging to turfgrass. No variety was spared, but St. Augustine and zoysia seemed to be most affected. Zoysia is our least drought tolerant warm season grass.

The main symptoms from the heat on the grass are what I call a bleached look in various patches in the yard. The ones most affected were the hottest places in the yard. Some have been large patches in areas of the lawn while others have been small. I had some small patches show up in the St. Augustine in my backyard. In St. Augustine it will look similar to chinch bug damage.

Our warm season grasses vary in their tolerance to high temperatures. Bermuda takes it the best and, as I said earlier, zoysia the worst. And a lot of damage can depend on other factors such as exposure to sun, reflected solar radiation from windows or other reflective surfaces, close proximity to streets, sidewalks, and paved surfaces, and the overall health of the grass prior to the heat.

Quite often, as has been our case, extreme high temperature is combined with drought injury. After a good rain, the grass can take the hot weather much better than with irrigation water. The effect of high temperatures on turfgrass is the creation of metabolic imbalances.

Under normal ambient temperatures, plant enzyme systems become more active as temperatures increase. However, once temperatures exceed the optimum for growth, enzyme systems shut down.

In addition to reduced growth, temperatures above 105 degrees can break down these enzymes causing plant injury. While ambient temperatures rarely go above this threshold in the Augusta area, turfgrass canopy temperatures can exceed this temperature, especially under drought stress.

Drought-stressed turf canopies can have temperatures 15 to 25 degrees higher than ambient temperatures. In hot summer months, canopy temperatures have been shown to be cooler when turf is maintained at higher mowing heights.

Healthy, thick grass helps insulate the grass, while thin grass is more susceptible to the heat. This helps explain why the small spot in my backyard got burned by the heat, because the grass is thin in that area.

To help prevent any damage from happening again if the extreme heat returns this summer, wet down the turfgrass with a hose to keep the grass canopy cooler.

INDOOR ANTS

A major problem many of us have to endure this time of year is ants coming indoors. In most cases, they are small Argentine ants, sometimes called sugar ants. Carpenter ants, which are large and black, also come inside. Argentine ants are looking for sugary substances to eat. They also love dog or cat food. They nest outside in mulch or piles of leaf litter.

Carpenter ants normally they nest in hardwood trees with dead wood. If they nest indoors, it means you have water-damaged wood.

One of the most common ways ants reach our houses is from tree limbs touching the house.

Check thresholds and window frames to make sure there is a tight fit. Replace thresholds under doors if needed and caulk around window frames.


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