The Home Stretch: Guide to End of Summer Lawn Care

As we enter the month of August, the long days of intense sun begin to take their toll on our lawns. In all reality, it’s the soil that takes the abuse, not the foliage. After all, a blade of grass is essentially a miniature solar panel. It’s an incredibly efficient mechanism that absorbs light energy and converts it to chemical energy in order to create food from carbon dioxide and water, that’s its sole purpose. The point I’m making here is that more sunlight isn’t what causes our lawns to struggle during the hot summer months. The difficulty is maintaining moisture in the soil, which is the secret ingredient to having lush green grass all year long. Focus your end of summer lawn care efforts on the following objectives:

Objective 1: Moisture Retention

As temperatures rise, the air’s ability to retain moisture increases. This moisture is pulled into the air from every available source, including the soil beneath our lawns. In order to help retain this moisture, make sure to dethatch and aerate during the spring or fall. These processes improve the uptake of air, water, and nutrients by the lawn’s root system, but they also promote water loss if done during the hot summer months. You can also adjust your mower height setting to increase summertime moisture retention. Mowing higher allows the foliage to protect the topsoil from direct sunlight.

Objective 2: Drought Resistance

Once we’ve established good practices for retaining moisture, we’ve bought ourselves enough time to focus on more long-term solutions. Visualize Objective 1 as plugging a hole in a leaky bucket. Following that analogy, Objective 2 is the process of refilling the bucket, and making sure that it stays full. It’s generally accepted that a lawn needs at least 1 inch of water per week, either from rainfall or irrigation, to maintain its color. Higher volume and lower frequency (such as 1” once a week, or .75” every 5th day) is better than a light surface watering daily for a couple different reasons. First, shallow waterings are more susceptible to the effects of evaporation, which results in less moisture actually being absorbed by the roots. Second is root development. When water is applied only to the soil on the surface, the plant devotes energy to developing roots near the surface. However, when we water less frequently with higher volumes of water, the moisture saturates the soil deep below the root structure. This stimulates the plant to develop roots deep in the soil, where it is protected against evaporation and able to absorb moisture long after the surface layer has been baked dry by the summer sun.

Objective 3: Reduce Stress

While water retention and drought resistance are most critical to surviving the summer, reducing lawn stress factors are also important to keep the turf in tip-top shape. To provide optimum growing conditions the pH level of the soil needs to be slightly acidic, somewhere between 6 and 7. The pH scale is a measurement of how acidic or basic (alkaline) a substance is. Within this range, turfgrasses are best able to absorb nutrients and thus maintain their color and vigor. Fertilization increases the acidity of the soil, but spreading lime will compensate for this. Also, mowing habits can be a major source of lawn stress. Mower blades should be sharpened at least annually for cleaner cuts, which require less energy to regenerate than the jagged, brown tips caused by a dull blade. Mowing frequency should also be determined by blade growth, not on a predetermined schedule. When 1/3 of the blade has regrown, it is time to mow again. This minimizes the amount of energy the lawn uses for foliar regeneration so that more energy can be allocated to root system development.

Simply being conscious of moisture retention, drought resistance, and stress factors is fundamental to maintaining soft, green grass late into the summer season. Grasses are simple organisms that, at a basic level, need only sunlight, water, and air to thrive. The complexity lies in the timing, method, and degree of application of each. As they say, the devil is in the details.

Author: Brad Turner

