In most regions, maintaining a lush, green lawn through summer hinges on watering. Sharpen your irrigation skills and I’ll try to help you know what to do to prevent brown patches from cropping up in your yard this summer.
A healthy lawn of tall fescue has a deep root system and the highest drought tolerance of cool-season turf types.
- Kentucky bluegrass consistently goes dormant during drought, reviving when rainfall resumes.
- Warm-season grasses, such as zoysia, St. Augustine, bermudagrass, and centipede, thrive in warm conditions, developing deep root systems that make them better able to withstand drought. In general, warm-season grasses require 20 to 40 percent less water than cool-season grass types.
Your Soil Type - Different types of soil absorb and retain moisture differently.
The Region in which you live - Different regions receive different amounts of rainfall and summer weather conditions, which influences irrigation needs. Grass needs the most water when heat, drought, low humidity, and high winds prevail. It may be helpful earn to identify signs of drought and summer lawn stress so I’ll cove that more in depth in just a bit.
The Age of Your lawn - There’s one other key when determining irrigation frequency. While all lawns need consistent moisture to remain green and healthy, newly planted lawns are in a critical stage for the first year. Don’t rely solely on rainfall to establish a healthy, deep root system – provide supplemental irrigation during the first year of growth. During this critical period of early growth remember that watering deep and infrequently encourages deep root growth – don’t let the new grass dry out but don’t water it everyday either!
During the scorching hot months of summer, conservation is key when it comes to watering and lawn care. Here are a few tips to ensure that not a drop of water goes to waste when watering your lawn this summer.
Choose your water delivery system carefully - For small lawns, try a hose-end sprinkler. Use a timer of some sort (even an oven timer will work) to help you remember to turn it off. With in-ground irrigation systems, use low-volume, low-angle sprinklers with heads that suit the size of the area you’re watering. Angle heads as low as possible to minimize evaporation. If you spot a fog or fine mist, that means that your system pressure is too high. Newer rotary nozzles (also called stream sprays or rotators) apply water slowly and evenly.
Watch your watering - Take the time, periodically, to observe the water distribution to ensure that you are not watering hard surfaces (causing runoff) or creating puddling on the lawn (applying too much water too quickly for soil to absorb it effectively).
Tinker with the timing - Add a smart timer that adjusts irrigation based on local weather conditions such as rainfall, temperature and even evapotranspiration rates. Water an hour or two before sunrise to minimize evaporation and take advantage of calmer winds. Time irrigation to avoid high water use hours in your household and community. Avoid night irrigation to prevent disease.
Fine-tune the watering duration - Measure how much water your system releases by evenly spacing six (or more) straight-sided containers (such as tuna fish or cat food cans) in the area you’re watering. Run your irrigation system for 20 minutes. Measure the amount of water in individual cans, adding them and dividing by the number of cans to get an average. Multiply the average by three to determine how much water your system releases in an hour.
Shorten select water cycles - With clay soils, slopes, and other areas where water runs off quickly, use short watering cycles on separate days to minimize runoff.
Inspect your water delivery system - Two clues that valves need to be repaired, cleaned, or replaced are leaking sprinklers and/or water-filled valve boxes. Fix leaks or unclog heads according to the manufacturer’s instructions. Replace damaged or broken heads as needed. I recommend purchasing an extra head or two to keep on hand so that, when needed, you can replace a damaged head right away – most sprinkler heads are rather inexpensive and easy to change out.
Reset your watering schedule frequently - At least seasonally, reset your watering schedule. Check with your local water authority for recommended irrigation schedules based on records of average weather conditions.
When summer sizzles, a lawn can easily fizzle, trading lush green for crispy brown shades. The causes of brown grass vary. Insect feeding, drought stress, soil compaction, or other factors can combine with heat to damage grass. In this weakened state, a lawn is more susceptible to attack by weeds and insects. Some simple detective work can uncover the culprits behind brown summer lawns. Learn what to look for when lawn brownouts occur and what to do to keep grass healthy.
Drought StressLike any plant, grass reacts to summer’s high temperatures and lack of water with wilting, browning, or even death. Here’s how to detect drought stress:
- Locate a brown patch, and pull on the grass. If it won’t pull easily from soil and is firmly rooted, it’s likely brown due to drought.
- Push a screwdriver into soil in brown and green lawn areas. If the blade slips easily into green lawn and won’t penetrate brown, the soil is dry. In rocky soil, dig a small hole to check soil moisture.
- Look at the lawn as a whole. When drought is the culprit, brown patches appear randomly and in rough patterns. Lawn near a sprinkler head may be green, while lawn further away is brown. Grassy areas in shade remain greener when parts in full sun turn brown due to drought. Lawn in low spots will remain green while higher areas turn brown.
- Learn the early signs of drought stress. Footprints that remain on your grass after it’s walked on (as in the photo above) means your yard is thirsty. Kentucky bluegrass develops a grayish cast, while other grasses become darker hued. Grass blades may also wilt. If you hear a distinct crunching sound when you walk on your grass if is really thirsty!
During periods of hot, dry conditions, both cool- and warm-season grasses can go dormant as a protective measure. If grass receives sufficient moisture, growth slows and blades remain green. During times of prolonged drought without irrigation, grass turns brown. If grass turns brown, don’t irrigate it unless you plan to continue watering the rest of the summer. When grass shifts out of dormancy, roots are depleted of food reserves, making plants susceptible to further stresses.
Don’t let newly established lawns go dormant. With a limited root system, a new lawn might not survive dormancy without extensive injury.
It varies by region, but grass that’s completely dormant may take up to three to four weeks, as irrigation is provided, to turn green. Providing more water than a lawn needs doesn’t hasten awakening from dormancy. You also may have to reseed a lawn that has gone dormant, especially with cool-season grasses. In my part of central Texas our lawns go brown in the heat of summer and green back up when the fall rains begin to fall.
Lawns also turn brown during summer due to insect activity. To determine if root-munching insects are present, pull firmly on brown grass. If it slips from soil and few or no roots are present, white grubs may be to blame. To learn more about grub control and how to identify a grub infestation in your yard, contact your local extension office.
Other insects eat grass blades not the roots, which causes lawn patches to appear as if they have been mowed too closely. Insects that attack lawns during summer include white grubs, chinch bugs, sod webworms, army worms, and cranberry girdler. Check with your local extension office to learn which pests plague which grass types in your area, the best methods for insect control, and how to deal with an insect infestation.
Fertilizing cool-season grasses during summer, cutting grass too short, and over-watering can weaken turf to the point that the grass becomes thin, exposing soil to weed seeds and insects. A lawn that’s frequently used for parking or does not receive regular aeration is more likely to have compacted soil, which produces poorly rooted grass that struggles to survive even when moisture is plentiful. Avoid heavy foot and vehicle traffic on lawns during drought.
Summer is also the time when many lawn diseases attack, and lawns that are stressed due to drought are more susceptible to disease organisms. Other conditions that predispose a lawn to disease include consistently watering after dark and mowing with a dull blade that tears grass. The jagged, torn edges create more openings for disease organisms to enter grass blades. One of the very best things you can do for your lawn is to mow with sharp blades!