Climate-Based Management of Lawns
http://edis.ifas.ufl.edu/ ( Publisher's URL )
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Permanent Link: http://ufdc.ufl.edu/IR00001520/00001
 Material Information
Title: Climate-Based Management of Lawns
Physical Description: Fact Sheet
Creator: Miller, Grady L.
Publisher: University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication: Gainesville, Fla.
Acquisition: Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
General Note: "First published: September, 2001"
General Note: "AE 319"
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Source Institution: University of Florida Institutional Repository
Holding Location: University of Florida
Rights Management: All rights reserved by the submitter.
System ID: IR00001520:00001


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Climate-Based Management of Lawns1 Grady L. Miller, Sydney Park-Brown, Caro l Stiles, Michael Dukes, Fred Royce, Jim W. Jones, Fedro S. Zazueta, and David Zierden2 Recent advances in atmospheric research ha ve made it possible to predict climate, with a relatively high level of certainty. K nowledge of climatic conditions allows us to develop a seasonal management st rategy for the lawn and other landscape features -particularly in irrigating, mowing, fertilizi ng and preparing for pests and diseases. This publication provides recommendations on strategies for managing turf given that future climate conditions are predicted based on the El Nio phenomenon. The New Science of Climate Prediction Weather is the atmosphere changing from day-to-day: a rainstorm or a cold snap. Climate is weather averaged over several months: a wet summer or a cold winter. Until recently, it was very difficult for mete orologists to predict the climate of upcoming seasons. Because of its size, the Pacific Ocean play s a major role in regulating the earth's climate. Oscillations of the Pacific Ocean's sea surface temperature above and below normal are a common occurrence. In 1982-1983, the world's climate was aff ected by a strong te mperature increase in the Pacific Ocean. This brought frequent winter storms to California and high rainfall along the Gulf of Mexico Coast, while other parts of the country experienced a warm and dry winter. As a result, world attention focused on the influence that the ocean has on climate. It was observed that ocean temperatures affect climate because they shift the positi on of the jet stream across the continent. This in turn influences fronts and ot her weather systems for several months. Because the jet stream is strongest in winter months, climate shifts are more pronounced in the cold season. Careful study of these phenomena led to the ability to predict climate us ing sea surface temperature. 1


When the temperature of the Pacific Ocean is higher than normal the phenomenon is referred to as an El Nio event. When the temperature of the Pacific Ocean is lower than normal the phenomenon is referred to as a La Nia event (See Fig. 1 ). When the temperature is normal, the event is referred to as neutral. CREDITS: Mike Halpert, Climate Prediction Center, National Weather Service, NOAA Figure 1 Sea surface temperatures in the easte rn equatorial Pacific Ocean define El Nio and La Nia. Warmer sea temp eratures mean El Nio, while cooler temperatures in this equatorial region indicate La Nia. The panels show the amount (in degrees centigrade) that sea surface temperatures were above the longterm average during a particular El Nio period, and the amount that they were below the long-term average during a La Nia period. Notice the spread of warmer-than-average (orange-red) water to the coast of North, Central and South America the El Nio year. Also, remember that El Nio and La Nia correspond to temperatures in the equatorial Paci fic Ocean. Other areas of the Pacific and other oceans may or may not follow this pa ttern. EQ indicates "Equator." Each 20 degrees of latitude is marked north a nd south of the Equator. Meridians are marked every 30 degrees E (east) and W (west) of Greenwich, England along the bottom of each map. The scale beneath each map indicates degrees centigrade below or above the long-term average temperature. El Nio typically brings 30%-40% more rainfall and cooler temperatures to Florida in the winter, while La Nia brings a warmer and much drier than normal winter. Table 1 summarizes the effects of El Nio and La Nia on Florida's climate. Note that in Table 1 El Nio/La Nia e ffects start in Oct ober and peak during January through March. They are weaker during April throug h June. Also El Nio/La Nia has little effect during the months from July through September. 2


How Do I Know If This Year Is El Nio, La Nia or Neutral? Information about the current El Nio/La Nia status and the implications for Florida climate are provided by The Florida Consortium and can be found on the Web at http://fawn.ifas.ufl.edu Table 1 Influence of El Nio/La Nia on Florida Rainfall and Temperature Seasons PHASE Oct-Dec Jan-Mar Apr-Jun Jul-Sep El Nio Wet Cool Strong Wet Strong Cool Weak Dry Normal La Nia Dry Weak Warm Strong Dry Strong Warm Weak Wet Normal Weak Cool Neutral Normal Normal Normal Normal Recommendations for Lawn Management Turf growth, quality, and its associated pests and diseases depend largely on climate conditions. Advance knowledge of likely climate conditions allows the landscape manager to prepare in advance a strategy to maintain the landscape system. For example, with knowledge that a wet warm climate period is approaching, the manager can: Prepare for fungal disease control Use slow-release fertilizer Adjust irrigation schedules to appl y water in the early morning when temperature and humidity are near de w point -do not irrigate during the evening or night. Likewise, knowledge of an upcoming dry pe riod, or a risk of drought, will give some opportunity for managers to enc ourage deep root growth by increasing irrigation intervals and wate r application amounts. In a ddition, weakened turf may be susceptible to insect attacks. Forward strategic planning will result in actions that will improve management, augmenting the quality of the turf while reducing costs, use of resources and environmental impacts (see Table 2 ). 3


Table 2 Recommended Practices for Managi ng Lawns in The Landscape Based on Climate Conditions Generated by Climate Management Dry Normal Wet Mowing Raise mowing height: Saint Augustine Grass (SA) & Bahia Grass (BH) 4", Centipede Grass (CN) 3". Mowing frequency may be reduced, but important not to let grass grow higher than normal and then scalp, which will compound stress. Sharpen mower blades. Regular mowing height: SA & BH 3"-4", CN 1.5"2". Sharpen mower blades Regular mowing height: SA & BH 3-4", CN 1.5"-2". Sharpen mower blades Irrigation Irrigate to wet the soil deeply (8"-12") and less frequently. Avoid light frequent irrigations. Monitor stress carefully. Wait until 60% of turf shows stress to initiate an irrigation. Irrigate early morning or late at night. Over watering when water use is permitted does not improve the quality of the turf. Watch for dry spots and irrigate them with a hose, if permitted. Use conventional irrigation recommendations from IFAS Circular 829 Apply 1" of water when 40%-60% of the turf shows stress. If using an irrigation controller, make sure that you adjust the frequency seasonally, without changing the irrigation amount. Manually set irrigation timer, and install a rain shut-off device. Irrigate at half the rate of a normal year and only when 30% of turf shows stress. Irrigate in early morning when dew is present. Irrigating late afternoon or evenings may result in disease problems. Fertilizer Fertilize with minimum nitrogen (N) application and balanced potassium fertilizer. SA & BH 2 lbs per 1000 sq. ft., Cent no fert. Apply fertilizer as recommended in IFAS Document SL-21 Apply N fertilizer to meet quality expectations; SA 4 lbs, Cent 2 lbs, BH 3 lbs per 1000 sq. ft. Increased N loss; use at least 50% slow release N source. Insects Stressed turf is more susceptible to insects: mole crickets, sod webworms, army worms, cutworms and chinch bugs. Dry conditions may delay emergence of some insects. Inspect the lawn weekly at least twice per month to determine if damage is beginning to occur and whether insects are the problem. Follow recommendations on insect control in the FL Lawn Handbook and IFAS Circular 1149 Except for spittlebugs, fewer insect pests during wet year. Monitor for spittlebugs and for thatch buildup ( FL Lawn Handbook ). 4


Conditions Generated by Climate Management Dry Normal Wet Disease Monitor disease incide nce. Stressed turf may be more susceptible to take-all root rot and other diseases. Manage irrigation to avoid stress and irrigate during early morning. Mature grasses maintained by proper cultural practices are not likely to be severely damaged by diseases. For further information, see disease section of FL Lawn Handbook Higher disease incidence of Brown Patch, Leaf Spot, fairy ring, slime molds, root rot. Treat with appropriate fungicide and reduce irrigation to minimize wetness during night. Aerification Aerate dry areas to increase water infiltration and promot e deeper rooting. Lawn will generally not need aerification unless subject to repeated traffic beyond normal cultural practices. For further information, see IFAS Fact Sheet RF-LH032 Wet soils are subject to increased compaction. Aerification during late spring or early summer reduces compaction. Weeds More common in weak turf, particularly goosegrass, crowsfootgrass, sandspur. Some herbicides can cause additional phytotoxicity to turf, delay application of spot treatments, unless weeds are perennial and hard to control. Good cultural management that encourage a dense thriving turf, minimizes weed infestations. Monitor irrigation amounts and follow fertilizer recommendations. For further information, see IFAS Fact Sheet ENH-84. Some weeds are more common during wet years, particularly alligator weed, dollarweed, sedges and torpedograss. Footnotes 1. This document is AE 319, one of a series of the Agricultural and Biological Engineering Department, Florida Cooperative Extension Service, Institute of Food and Agricultur al Sciences, University of Florida. First published: September, 2001 Vi sit the EDIS Web Site at http://edis.ifas.ufl.edu. 2. Grady L. Miller, Associate Profe ssor, Environmental Horticuture Department.; Sydney Park-Brown, Extension Agent IV, Hillsborough County Office; Carol Stiles, Assistant Professor, Plant Pathology Department; Michael Dukes, Assistant Professor, Agricultural and Biological Engineering Department; Fred Royce, Graduate Assistant, Agricultural and Biological Engine ering Department; Jim W. Jones, 5


Professor, Agricultural and Biological Engineeri ng Department; Fedro S. Zazueta, Professor, Agricultural and Biological Engineering Department; University of Florida; and David Zier den, Assistant in Research, Florida State University. References The Florida Consortium. El Nio, La Ni a and Florida's Climate: Effects on Agriculture and Forestry. Florida State University, University of Florida, University of Miami. 1999. The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race color, se x, age, handicap, or national origin. For information on obtaining other extens ion publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences / University of Florida / Christine Taylor Waddill, Dean Copyright Information This document is copyrighted by the Univer sity of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all c onventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full cred it is given to the UF/IFAS, citing the publication, its source, a nd date of publication. 6