Turf Heat Stress and Fungus
As we all know, our region experiences many extremes in terms of weather conditions. During the winter months we see freezing temps/snow and during the summer our area can go through very hot & dry periods. The hot summer months can cause significant damage to the lawn and it’s important to appropriately diagnose any turf issues that are common as a result from the heat.
Below we’ll break down the two most common summer issues we see with our turf: Heat Stress and Fungus.
Heat Stress
Most turf in our area is considered to be “Cool Season Grass” and it gets that moniker from the fact that it does so well during the cooler seasons. The spring and fall bring out that dark green healthy turf look but during the summer months the grass doesn’t fair so well. We try to counter the hot dry months with a solid fertilizer program (N) and increased watering but it’s still very hard to keep some areas of the lawn healthy even with these measures.
One of the most common heat related turf issues we see during the summer is “Turf Heat Stress”. This is when the grass essentially shuts down due to the increased heat and lack of increased water to compensate. The first stage of heat stress will bring slowed growth but you won’t necessarily see the grass change color yet. Stage two can bring a slightly purple look, almost no growth, and the grass will be very dry when touching. With stage three the grass turns light brown and looks like straw/hay when holding in your hand.
The fact of the matter is that it’s tough to avoid some patches of heat stress from developing from June – August in our area since it can get so hot and dry. The nitrogen included with our fertilizer programs helps reduce chances of heat stress and also increased watering can reduce the possibility of the lawn drying out.
In our experience the overall best chance at avoiding heat stress is to have a professional sprinkler system installed and then to have a water management program developed by someone who is trained in Evapotranspiration Water Scheduling . This type of watering plan sets a “base” schedule for your property per your lawn’s soil type and conditions, evapotranspiration rates, sprinkler hardware on site, and local historical weather averages. Once your base schedule is created you’ll then increase/decrease a set percentage amount each month to compensate for seasonal changes.
Fungus
Commonly mistaken as heat stress, fungal disease is also a common turf issue that we experience in our region. If the lawn is looking lush and green but getting random brown patches within those green areas, it could be fungus (brown patch is the most common fungal disease). While it can look similar to heat stress, brown patch looks different up close because the blades themselves have brown spots on them and the area closest to the thatch layer will be warm and damp.
Most of the brown turf areas we see with the lawns we service are heat stress related, but we’ve also had to treat some with a fungicide to stop the spread of brown patch. When we diagnose a lawn to have a fungus problem we recommend 1–3 treatments with a fungicide, and it will treat and usually reverse the issue very quickly. These treatments are outside of our regular program and pricing starts at $149 per visit.