Practice No. 11. Healthy Turf Areas
It is possible to have an ecologically friendly turf, even if you choose bluegrass or turf type tall fescue. But it’s still high maintenance and high water-use. These turf areas can be maintained in an ecologically friendly manner. To me, that means no herbicides, pesticides, fungicides or chemical fertilizers.
My lawn wasn’t in the best shape when I made this decision to use organics in place of chemicals. In fact, I was embarrassed by it. It was weedy, yellowish green with thin turf and bare patches. My goal was a thick, green healthy turf. The road to turf health was a four-part program. I studied the proper way to care for my fescue turf and I made the decision to initially use a weed killer to lessen the weed problem. Immediately following that second part, I implemented a program to build the health of the soil with worm castings and composted manure and then over seeded the turf to fill in the thin and vacant areas.
These steps will help your achieve a healthy, lower water-use and lower maintenance lawn of bluegrass, fescue and bermuda turf grasses. The water use and maintenance are lower than before, but still considered high. These turf grasses are foreign to our soil and climate and require extra care, especially under extreme summer conditions. Buffalograss, America's only native turfgrass, is the low maintenance, low water-use alternative.
Thirteen steps to a healthy, lower water-use lawn.
- Turf bed preparation is all-important. Amend the soil with organic matter, and other materials for better drainage, if required. Fescue, bluegrass, ryegrass and bermudagrass are all high feeders. Amend soil with 6 – 12 inches of composted organic matter. Turf beds with ample organic matter require less water for growing a healthy turf than organically deficient soil. Soil amended well with organic matter helps buffer soil alkalinity for a greener lawn without adding nitrogen fertilizer. Adding inorganic amendments improves the drainage capacity of compacted clay soils.
- Reduce slopes and berms for water conservation. (Micro-niche awareness.)
- Lawnscape to avoid runoff situations and to avoid watering sidewalks and driveways. (Micro-niche awareness.)
- Match the turf grass with its appropriate maintenance. Warm season and cool season grasses have different requirements, as do the individual grass species.
- Select an efficient irrigation system based on turf selection,. Avoid mist systems. Adjust irrigation heads for larger droplets. Know how much your irrigation system puts out for your sprinkler cycle. Water your turf according to the turf’s needs and growth -- adjust your sprinkler timers for the seasons and precipitation received.
- De-thatch the turf if there is an accumulation of more than half inch of thatch – the buildup of undecomposed roots, rhizomes and stolens. Some thatch accumulation is normal, it's part of the life cycle of the grass. But when it accumulates faster than it decomposes and hinders water penetration it can also harbor insects and diseases. When water is prevented from soaking into the soil, turf roots remain shallow, close to the soil surface, causing the turf to suffer unnecessarily in heat and drought. The easiest way to remove thatch is by renting de-thatching equipment, or raking it out with a special de-thatching rake. In severe cases with excessive build up, the thatch may need to be removed in stages, over a period of 1 – 3 years even. Determine the best procedure by removing a plug or core to see the extent of thatch buildup and the root system. Over-seeding or re-seeding may need to be done after de-thatching. Thatch should be composted and spread over the turf or used as a soil amendment when decomposed.
- Properly feed your turf grass. Amend existing soil by topdressing with composted manure or other composted material. Top dress in the fall with ½ to ¾ inch layer of well composted material. Granular humate, dry horticultural molasses, alfalfa and cottonseed meal, alfalfa pellets are common organic amendments for turf. For healthier soil and longer term benefits, solid organic matter needs to be added to the soil. Liquid applications of compost tea, aerobically activated compost tea, liquid humate, liquid molasses, fish emulsion and other organic sprays add microbes to the landscape, stimulate microbial activity and give turf a boost in between topdressing. If you employ a lawn service, inquire whether they will feed lawns organically – some will.
- Mow high, mow often. Mow to the proper height, mowing not more than a third of the blade at any single mowing. Mow by growth rate of the grass blade, rather than by schedule. If we mow too low, we reduce the surface area needed for the leaves to store food (energy), thus weakening the plant during times of heat, cold, chemical or drought stress. If our grass dies or declines during this period, we wrongly conclude it died from extreme weather, when in fact, it died of carbohydrate shortages due to cutting the grass too low. Mowing low decreases shading of the soil, increasing evaporation. Mowing high shades the soil and cools the crowns, the temperature sensitive growing points of the turf grass. You may elect not to mow yourself, but hire a lawn service. Lawn services enforce their schedule on the lawn (refer to design theories, control oriented gardening). Proper mowing itself can go a long way towards a healthy lawn.
- Don’t bag it, use a mulch mower. Choose a lawn service that uses mulching mowers. Mulch mowers do not cause thatch – over watering and over fertilizing causes thatch by over stimulating growth in grass and by killing the beneficial microorganisms whose job is to decompose this matter. Mulch mowers with, blades sharpened periodically, will not leave visible clippings. Grass blades are finely chopped and forced to soil level for decomposition. When bagging lawn clippings, you will loose 50% of the nitrogen laid down with the first two mowings after fertilization. Mulch mowing returns the nitrogen to the soil in the form of clippings that will decompose quickly, averaging 20 – 25% of the turf's nitrogen needs. Mulch mowing spares landfill space.
- Sharpen the mower blades at least yearly. Jagged leaf blades cause disease, heat and drought stress and causes leaf dieback below the cutting point, thereby giving your turf a lower cut than intended.
- Water according to the need of the turfgrass, not on a schedule. Water an inch at a time. (In step 5, you should determine how long it takes to water an inch, then set your system for that). How often should you water an inch? Water according to the evapotranspiration (ET) rate for your turf type. ET rate is the combined water loss from soil, plants and weather conditions (temperature, relative humidity, solar radiation and wind speed) for Bermuda, Buffalo, Blue, and Tall Fescue grasses. The ET rate is represented by a number usually less than one inch, such as .19, .24 or .29, etc. If you find a local source for the ET rate, keep a log from the date of your last watering. When this total adds up to an inch or more, it's time to consider watering again. If it rains during this time period, subtract that amount of rainfall and wait until the total is at least 1 inch again. Buy and install a rain gage so you will know how much rainfall you receive, rainfall amounts vary greatly across the area. Remember, if your soil is well amended with organic matter, less water is required by the plant. The ET rate does not take into account the variety of soil conditions across the area. Another way to determine when to water is to test lawn areas using a soil probe or 6” screwdriver. If the soil probe or screwdriver can easily be inserted in clay or caliche soil, soil moisture is sufficient. If the probe cannot easily be inserted 6 inches, it’s probably time to water.
- Aerate and re-seed when necessary. Aeration in spring and/or fall helps to correct soil compaction. Compaction prevents irrigation and rainfall from soaking in. Aeration should be performed when the turf is actively growing and not during periods of excessive heat or drought.
- Re-seed thin areas of your turf to prevent weeds. A thick healthy turf crowds out weeds and prevents their germination. Re-seeding may be necessary for shady areas and when restoring a lawn.
Three factors are necessary for the appearance of plant disease: a virulent pathogen, a susceptible host and an environment conducive to development of the pathogen. Disrupting any of these conditions decreases the likelihood of infection.
If you have amended the soil for turf as for any other high water-use and high feeding plant, you will probably not encounter turf diseases. Beneficial microorganisms will be present to fight disease pathogens/organisms that create turf problems, even in lawns whose soil was not initially sufficiently amended. Soil building is not an instant solution to problems accumulated over time, but the turn around begins quickly. If you follow these 13 guidelines in caring for your turf, within a few years, disease problems will be minimal, perhaps non- existent.
If you suspect a fungus or insect problem, analyze what your maintenance practices are to determine the cause of the problem. Fungus and insect problems are not normal or routine conditions for lawns. Lawns can and should be healthy. Healthy soils contain organisms whose job is to fight and kill predator insects and pathogens. Properly diagnose the problem.
Grubs in turf is a common problem for turf owners. Noticing a few grubs in the lawn is not a problem, not all grubs are turf-eating grubs. However 5 or more grubs per square foot are indicative of a problem. Follow the steps in integrated problem management to manage the problem. Grubworms in organically maintained turf is rarely a problem.
For more guidelines on lawnscaping, turf selection and maintenance, click on the article for lawns.