Every time we have a dry period in spring or summer, I get those predictable calls about some mysterious pest that’s playing havoc in lawns.
Dry spots in lawn. Photo credit: Larry Williams
Without realizing it, the caller usually describes a textbook example of dry spots in a lawn. And many times that’s what the problem areas are – dry spots.
Dry spots are the result of imperfections in an irrigation system. They are revealed during dry weather. Adequate rainfall masks the imperfections in an irrigation system.
Possible imperfections are many. The homeowner may easily fix some irrigation system problems while other problems may require the expertise of a licensed irrigation contractor. There may be too few sprinkler heads for adequate coverage, insufficient pressure to operate each zone, incorrect choice of nozzles or wrongly mixing rotors with spray heads on the same zone. The cause for dry spots may be as simple as a maladjusted spray head, a broken spray head, a plugged nozzle, a tree or shrub blocking the water, grass that has grown over a pop-up spray head, etc.
Regardless of the cause, there are a couple of simple tests that can help confirm that the problem areas are to be blamed on lack of sufficient water vs. a mysterious pest.
First, check the affected areas by taking a soil sample in the root zone. Use a soil probe or shovel to remove a core of soil to a depth of 6 to 8 inches. Visually inspect and feel the soil sample for moisture. Do the same test in an area of the lawn that looks normal and compare the difference. It should be obvious if there is a difference in moisture between the areas tested.
The second test involves placing several empty straight-sided cans such as tuna fish cans in the affected area and several in a “normal” area of the lawn. Then let the irrigation system run long enough to collect some water in the cans. Compare the amount of water collected in the two areas. It should be obvious if there is a difference in the amount of water applied in the areas tested.
These tests are cheaper, less trouble and more environmentally friendly as compared to purchasing and applying pesticides for nonexistent pests as a result of incorrectly diagnosing the problem. If these tests do not identify the problem as lack of water, you may have a lawn pest. But don’t guess.
Occasionally inspect your irrigation system while it’s running for obvious, easily corrected problems such as a maladjusted or broken spray head. The following UF/IFAS Extension publications will help with your inspection. https://edis.ifas.ufl.edu/entity/topic/residential_sprinkler_systems
Plants need water. This isn’t an outrageous insight, but the details behind this statement can be more complicated than it might seem. While it is true that plants, like all living things, need water to survive, they don’t all need the same amount and they may need more or less at different times. For a healthy landscape, garden, container planting, or lawn, it’s important to pay attention to the little quirks of watering that may not be immediately obvious.
During the wintertime, temperatures are lower and days are shorter. Less heat and sunlight means water will evaporate much more slowly and the soil will stay wetter. With less heat and sunlight, plants grow at a much slower rate (if at all). This means that irrigation systems set for summertime watering are probably going to keep conditions too damp for many plants during the winter. For example, a St. Augustinegrass lawn might only be able to survive 1 to 5 days without irrigation or rain in the summer, but the same lawn can last 8 to 28 days between waterings in the winter. Consider adjusting your irrigation system or watering schedule to account for seasonal differences. Remember also that a practiced eye can tell when a lawn needs water – folding or curled blades of grass, a dulling of color from bright green to bluish-gray, and footprints that remain in turf rather than springing back are signs of drought stress. Before these signs show up, it may not be necessary or beneficial to water.
Snails love moisture, and an abundance of them may be a sign of too much irrigation.
If plants are overwatered, they often show different signs of distress. Lawns may have more issues with fungal diseases or become patchy, which can let weeds begin to take over. Ornamental plants such as shrubs and trees might show signs of nutrient deficiency or begin to drop leaves, appearing sparse and unhealthy. You may notice an increase in moisture-loving pests as well, such as slugs or snails. Check for watering issues if you notice any of these symptoms.
Cooler weather can be a good time to get outside and do regular maintenance on irrigation systems and plantings. Replace or unclog malfunctioning nozzles, patch
Moisture held against the base of a tree by mulch can eventually damage the plant.
holes in water lines, and adjust irrigation heads that may no longer be pointed in the right direction. Prune back plants that have grown into irrigation sprinkler patterns and may disrupt even watering. Put in new or replacement plants and make any adjustments needed to their irrigation. Lastly, add mulch around plants. This can help retain soil moisture, even out changes in soil temperature, suppress weed growth, and add organic matter to the soil as mulch breaks down. Avoid piling mulch against the base of plants, however, or it will hold moisture against the plant and can promote the growth of molds and other fungi.
Improperly placed or calibrated sprinklers can cause problems.
Your lawn will likely need supplemental water during the growing season. Instead of setting your irrigation system to come on every few days, learn exactly when your grass needs water with Turfgrass Talk from your UF IFAS Extension Panhandle Horticulture Team. You may then apply water when it is needed by the grass, helping to prevent turf issues from overwatering.
Success in the garden can occur with proper watering. Learn several ways to water to your vegetables In the Home Garden with UF IFAS Extension Escambia County.
Weeds identification and management is still one of the most common questions we receive at the local UF IFAS Extension office. Learn about the chamberbitter weed that can grow in turf and ornamental beds and the multi faceted approach that is necessary for management In the Garden with Beth Bolles, UF IFAS Extension Escambia County.
