HOW TO PROTECT YOUR LAWN AND TREES DURING EXTREME SUMMER HEAT

When your lawn begins wilting and your trees begin scorching during extreme heat, your first instinct may be to water more. Before adding another full irrigation cycle, check the soil. The problem may not be too little water. It may be too much.

During extended periods of temperatures near or above 100 degrees, cool season grass often looks stressed during the hottest part of the day. The blades may fold, develop a gray green appearance, or remain flattened after being walked on. These symptoms can make the lawn appear severely dry, even when adequate moisture is still present beneath the surface.

Responding to every sign of afternoon stress with another deep watering cycle can create serious problems for both the lawn and the trees growing within it. There is an important difference between watering the soil and cooling the grass, and understanding that difference can help protect your entire landscape.

Syringing is a short daytime irrigation cycle used to lightly wet and cool the grass canopy. It is not intended to deeply water the soil. As the small amount of water evaporates from the grass blades, it temporarily reduces the temperature of the turf and relieves some of the immediate stress created by intense sunlight, wind, and heat.

Deep irrigation replenishes moisture within the root zone. Syringing cools the grass canopy. These are two different practices with two different purposes.

Syringing should never replace the deep watering your lawn and trees actually need. It should replace the unnecessary additional watering cycles people often add because the grass looks stressed during the afternoon. If the soil is dry, the root zone may need water. If the soil is already moist, adding another full irrigation cycle can do more harm than good.

This is especially important in Central Kansas, where many soils contain a high percentage of clay. Clay soil can hold a tremendous amount of water, but it can also drain slowly and contain limited air space. Plant roots require both water and oxygen to function properly.

When soil remains saturated, the spaces that normally hold oxygen become filled with water. As oxygen levels decline, root function begins to suffer. Fine absorbing roots can weaken, and the plant becomes less efficient at taking up water and nutrients.

Your lawn and trees share this same soil environment. Every unnecessary watering cycle added for the grass also affects the tree roots growing beneath and around it. While the lawn may show temporary improvement after additional watering, the tree roots may be struggling in soil that has remained wet for too long.

This can create a confusing situation. A tree surrounded by wet soil may begin showing symptoms that resemble drought. Leaves may wilt, develop brown edges, turn yellow, or drop earlier than normal. The canopy may begin thinning, and the tree may appear unable to tolerate the heat.

The natural reaction is to add more water, but sometimes the tree is not struggling because water is unavailable. It is struggling because the roots do not have enough oxygen to absorb and move that water effectively.

Trees rely on a process called transpiration. Water is absorbed by the roots, moved upward through the tree, and released through tiny openings in the leaves. This movement helps transport nutrients and cool the leaf surface.

For transpiration to work properly, the roots must remain healthy and active. When soil is saturated and oxygen is limited, root respiration slows. The leaves continue losing moisture to the hot, dry air, but the root system may not be able to replace it quickly enough. The result can be wilting or leaf scorch, even when the soil contains plenty of moisture.

This does not mean that every scorched tree is being overwatered. Scorch can also be caused by drought, extreme heat, strong wind, compaction, restricted roots, vascular problems, or several stresses occurring at the same time. The important lesson is that scorch is a symptom, not a diagnosis.

Do not assume that a struggling lawn or scorched tree automatically needs more water. Check the soil before making that decision.

Syringing provides another option during extreme heat. Instead of adding a long irrigation cycle that pushes more water into the soil, a brief daytime cycle lightly wets the grass blades and allows evaporation to cool the canopy.

Syringing is normally most effective between approximately 11:00 AM and 3:00 PM. Rotor zones may run for about five to ten minutes. Maxi Paw zones may run for about ten to twelve minutes. Spray zones may run for about three to five minutes.

These times are only starting points. Actual runtimes will depend on water pressure, head spacing, wind, sprinkler output, and site conditions. The goal is to lightly wet the grass blades without creating runoff or deeply soaking the soil.

During severe heat, a second light syringing cycle may be helpful. Before adding another cycle, make sure the water from the first cycle has evaporated and the grass is still showing signs of heat stress. The water should not remain on the grass late into the afternoon or evening.

Healthy summer irrigation requires observation and restraint. Water deeply when the root zone actually needs moisture. Allow enough time between watering cycles for oxygen to return to the soil. Use brief daytime syringing cycles when the grass needs temporary relief from extreme heat.

The appearance of stress does not always mean the soil is dry. Sometimes the healthiest decision for your lawn and trees is not to add more water, but to use the water you apply more intentionally.

Water the soil when the roots need moisture. Cool the grass when the canopy needs relief. Check the soil before deciding that more water is the answer.

Reach out to us at 620-282-2076 for more information or if you’d like us to assist you in setting up your syringing cycles on your system for you!