Most of us do not experience stress throughout the summer, but it’s a different story for our lawns. A browning of the grass and new weeds and pests are symptoms of heat stress, which can develop when the weather is consistently hot and dry for an extended length of time. When you reside in a region that is presently undergoing a drought, heat stress can be worsened.
What is Lawn Stress?
Discoloration of the grass is a telltale symptom of lawn stress. When you look at a “crispy” lawn in the summer, do you ever see any brown or yellow spots? That should have been a red flag that the grass is in a lot of pain.
Additional symptoms, such as browning and curling grass blades, may become apparent as summer advances and the lawn stress levels rise. Regrettably, grass has a more difficult time absorbing nutrients and minerals when a lawn is stressed.
Heat stresses out grass, particularly the roots, even though summer is a wonderful time to be outside. Many lawns go bare in the summer due to the high temperatures, sunny days, warm nights, and lack of precipitation. To preserve energy when the temperature outside rises, underground plant roots contract to use less water. In extreme heat, grass may also draw on energy stored in its roots to stay alive.
Despite these natural responses to heat, heat stress and drying out can still happen to grass. Intense or prolonged heat causes grass to dry up and eventually die from a lack of water, a condition known as heat stress. While all grasses are subject to heat stress, some are more vulnerable than others. In the scorching summer heat, cool-season grasses are more likely to wilt and become infected. When the soil temperature goes over 85, these grasses risk root injury.
What is Drought Dormancy?
Plants can’t survive without water since it makes up around 80% to 95% of their total mass. It is believed that transpiration and guttation account for up to 99.5% of water loss. Transpiration will be the primary process discussed in this article. What we call “transpiration” actually happens when water moves through a plant and then evaporates from its stems, leaves, and other aerial components. Plants rely on transpiration to ward off the scorching summer heat and propel nutrient uptake from the soil. Because of this, water is crucial for flourishing grass.
Drought affects plants differently. Extensive root systems allow plants to survive drought by accessing soil water that would otherwise be inaccessible to plants with shallower roots. In order to survive dry spells, plants can set seed just before they die. This way, when better weather conditions come along, the seed will continue the family name. Lawn grasses often go into dormancy as a means to evade drought. This drastically lowers the plant’s water requirement, enabling it to survive dry spells until rain or irrigation is accessible. Even because grass is “drought-tolerant,” it doesn’t necessarily mean it will remain verdant all year long. Grass species that experience both warm and cool seasons go through dormancy, which is a crucial step that allows them to endure prolonged drought.
Cool and Warm Season Grasses
There is an ideal range of soil and air temperatures for the growth of cool-season grasses, such as fine fescues, tall fescue, perennial ryegrass, and Kentucky bluegrass. This is also the case with warm-season grasses, such as St. Augustinegrass, Zoysiagrass, Bermudagrass, and Centipedegrass.
When temperatures drop below ideal in the winter, warm-season grasses are much more prone to suffer damage from temperature fluctuations. However, heat stress is a major problem for cool-season grasses in the summer. Because photorespiration is an inefficient process, cool-season grasses can still be damaged by heat stress even when watered enough.
Recall the molecules of carbon dioxide that are necessary for photosynthesis in your lawn. It so happens that RuBP, the molecule in charge of fixing CO2, also fixes O2 molecules through an inefficient mechanism known as photorespiration. Raising the temperature further increases RuBP’s affinity for oxygen. You have a two-pronged monster waiting to devour your cool-season lawn: poor photosynthesis and an increase in respiration (read: greater demand for food) brought on by higher temperatures.
Air temperatures in the summer are frequently much higher than what plants need to undergo cool-season photosynthesis, and soil temperatures can be higher than what plants need for root growth for long periods. If this occurs, the plant’s photosynthetic capacity drops significantly, and it may stop producing roots altogether.
If left unchecked for a long time, your lawn may soon exhaust its energy levels. If photosynthesis is unable to provide enough food and root growth is impeded, then it is highly logical for the plant to fall dormant until lower temperatures come.
Indications of Lawn Stress in Summer
If your lawn starts to seem unhealthy, like it’s turning gray or a darker green before turning brown, or if footprints stay on the grass for hours after you walk on it, it could be time to water it and an indication of summer stress. Moreover, grass blades can get brown at the tips when stress starts to significantly affect your lawn. There are a number of issues that can be causing brown patches in your yard, and dryness is making them worse:
Since the larvae of these insects feed on the grass roots, you can have a grub infestation if the grass in certain spots can be lifted up like a carpet. If you observe any of these symptoms in your yard, your grass will have a very hard time absorbing nutrients. To prevent your grass from withering or drying out in the scorching summer months, it is advisable to take measures to protect it from heat stress.
Tips to Reduce Lawn Stress in the Summers
Keep Off the Grass
Walking on freshly moistened grass causes the blades to bounce back. When the grass isn’t getting enough water, it becomes more worn down and more susceptible to injury. Compacted soil prevents air from reaching grass roots, another consequence of excessive foot movement on damp soil.
Seasonal Rest
Your lawn may enter a “dormant state” as a defense mechanism against drought and stress if it is left unattended. When the temperature becomes too high, grass will basically die out until the weather becomes cool and wet again. Always go for water deep, but not daily. Every week, your grass needs at least an inch of water. And water at least twice, preferably three times, per week. It is recommended that you water your lawn once a week while this condition lasts.
There is an exception to every rule. Because young turf has weak roots and might not be able to bounce back from severe stress, letting it dry up and die can have devastating long-term consequences. In order to maintain these lawns healthy and green, it is essential to water them regularly and avoid compacting the soil.
Keep the Soil Loose
Soil compacting from heavy foot traffic or mowing machinery makes it hard for air to reach the roots of your grass. If this is an issue for your grass, aeration will help alleviate the pressure. In the event of a heat wave, it is advisable to forego mowing the lawn completely, particularly during the peak hours of the day.
The combination of hot temperatures, wear and tear from mowers, foot traffic, and other stresses can permanently destroy the grass. When you really must mow the grass, try to do it in the wee hours of the morning or the cool of the evening.
Maintaining a Sharp and Height
When grass is trimmed using dull mower blades, it loses more moisture due to shredding. Additionally, the lawn takes on a dreary appearance when the shredded tips turn dark. Put your mower blade on one of the higher settings because most types of grass like it mowed high. The deeper the roots of taller grass grow, the further down in the earth they may reach for moisture.
Test Fertilizing
Your grass requires nutrients to thrive. But hold off on the fertilizer for a second; grass requires a lot of energy to flourish, and planting grass in the middle of summer could put too much strain on your lawn.
Final Verdict: When Is the Best Time to Fertilize?
A smart fertilization program takes a proactive approach to grass health, taking your lawn in the best possible condition when faced with environmental stresses like heat and drought. Fertilization should not be done in response to stress but rather in preparation for it.
That is also sound advice for items that aren’t fertilizers, like humic acid and seaweed extract. Instead of trying to salvage your lawn in the midst of a protracted heat and drought crisis, condition your soil all year round. Keep in mind that your grass is probably not dying; it is only entering a dormant period and will emerge when the weather warms up.
Choose the best for your law soil in the scorching heat of summer and keep it healthy with WeedX Fertilizing.