- - AGRICULTURE CORE CURRICULUM - - (CLF6000) Advanced Core Cluster: ORNAMENTAL HORTICULTURE (CLF6700) Unit Title: LANDSCAPE DESIGN, CONSTRUCTION, AND MAINTENANCE ____________________________________________________________________________ (CLF6703) Topic: TURF IN THE LANDSCAPE Time Year(s) 5 hours 3 / 4 ____________________________________________________________________________ Topic Objectives: Upon completion of this lesson, the student will be able to: - Cite the requirements for selection, installation and maintenance of turf - Demonstrate an understanding of the requirements and uses of turf as they relate to the following: Learning Outcome #: (M-2) - Prepare a simple landscape design. (M-4) - Design a turf and shrub sprinkling system for an area specified by the instructor. Special Materials and Equipment: Enough sod to plant a small sod lawn, and the necessary landscaping tools, including rotortiller, shovels, bow rakes, roller, and linoleum knife. References: Cotton, Lin. (1985). ALL ABOUT LANDSCAPING. Available from: Ortho Books, P.O. Box 5047, San Ramon, CA 94583. Hannebaum, Leroy. (1981). LANDSCAPE DESIGN: A PRACTICAL APPROACH. Reston, VA: Reston Publishing Company. Hartmann, H. T., Flocker, W. J., & Kofranek, A. M. (1981). PLANT SCIENCE: GROWTH, DEVELOPMENT, AND UTILIZATION OF CULTIVATED PLANTS. Englewood Cliffs, NJ: Prentice-Hall. Ingels, Jack E. (1987). LANDSCAPING (3rd ed.). Albany, NY: Delmar Publishers. Editors of Ortho Books. (1985). ALL ABOUT LAWNS. Available from: Ortho Books, P.O. Box 5047, San Ramon, CA 94583. Editors of Sunset Books and Sunset Magazine. (1984). LANDSCAPING ILLUSTRATED. Menlo Park, CA: Lane Publishing Co. Editors of Sunset Books and Sunset Magazine. (1988). WESTERN GARDEN BOOK. Menlo Park, CA: Lane Publishing Co. Evaluation: Unit Exam ===================================================================== *** INSTRUCTORS PLEASE NOTE *** The detail of this topic presentation goes beyond the scope necessary to meet the requirements of the Core Cluster in this area. It will take longer to teach than indicated above if covered entirely. It is included for local enrichment as appropriate to the class. ===================================================================== TOPIC PRESENTATION: TURF IN THE LANDSCAPE REVIEW: (CLF6453) Sprinkler Irrigation Systems provides complementary information on developing irrigation for turf. A. Turf as a Landscape Element: When most people think of a landscape, they think of a lawn or turf area surrounded and enhanced by other plants and amenities. The lawn is the centerpiece of most residential and public landscapes. While turfgrass is not necessary for a beautiful landscape, it certainly has been, and remains today, the most-desired landscape element by the American public. Well maintained turf is beautiful and can serve many purposes. 1. Uses of Turf: Turf serves many purposes, both from a functional standpoint, and from a design perspective: a. Recreation: Whether a backyard play area, a park lawn, a football field or a country club putting green, turf is unparalleled as a playing surface. Turf, more than any other plant, takes wear and abuse while providing a soft uniform surface for recreation. b. Ground cover: Turf prevents erosion, keeps dust and dirt down, and helps absorb runoff from rainfall. c. Cooling: Taking up and releasing more water than any other landscape feature (including swimming pools!), turfgrass has the effect of cooling adjacent areas. Also, turf absorbs light and heat, rather that reflecting them as a paved surface would. d. Visual Foil: From a visual standpoint, turf provides a neutral, even area in the landscape next to which featured amenities and plants can stand out. The calming effect of a green lawn is well recognized. e. Visual Accent: In some small, urban landscapes, a patch of well-kept turf can actually serve as an accent, providing the area with a splash of emerald-green color. 2. Advantages and Disadvantages: While lawns are useful and much- desired in the landscape, there are difficulties associated with them as well: a. Advantages: Most of the reasons turf is so widely planted are listed above. Some additional advantages of turf are: 1) Turf is relatively inexpensive and fast to install, compared with most paving and ground covers. 2) Turf is easy to repair or replace if need be. b. Disadvantages: Most of turf's disadvantages relate to its maintenance requirements. Turf is, by far, the most maintenance-intensive element in the landscape. 1) Lawn grasses use more water than any other part of the landscape. For this reason, landscapes in arid areas are being planned with fewer and smaller lawns. 2) Lawns require frequent mowing. This is a labor- intensive, and therefore expensive, operation. Mowing is also noisy, which is a problem in certain locations. 3) Turf requires relatively high levels of fertilizer, which can be costly, and can impact runoff and soil-water adversely. 4) Most turf types are subject to infestations of various pests, especially if their needs for water, mowing or fertilizer aren't met. Controlling pests in turf can be expensive, time-consuming, and pose environmental problems. 5) Turf is impractical for steep slopes or areas difficult to access with power machinery. 3. Requirements for Healthy Turf: To be successful with turf, three basic requirements must be met: a. Choose an Appropriate Turf Species: The best maintenance possible will not keep a poorly selected turfgrass in good condition. Climate, light, use patterns, and resources for maintenance, all must be considered when choosing a turfgrass. b. Establish Turf Properly: Grasses must have good growing conditions at installation, or turf establishment will be uneven and prone to pest infestation. If properly established, turf is relatively straightforward to maintain. c. Maintain Turf Correctly: Consistency and attentiveness are the keys to maintaining healthy turf. These three requirements are discussed in further detail below. B. Choosing a Turf Species: 1. Turf and Climate: The right turf in the wrong climate will not succeed. While local vendors will not sell turf species poorly adapted for their area, site-specific conditions such as microclimate can affect the choice of turfgrass. a. Cool-Season Grasses: 1) These grow well in northern latitudes, at high elevations elsewhere, and in parts of the country that have winter snow. 2) They grow most actively in the cool spring and fall, and slowly in the hot summer. 3) With enough water, they will remain green all year. 4) Common cool-season grasses include Kentucky bluegrass, fescue grass, bent grass, and ryegrass. b. Warm-Season Grasses: 1) Warm-season grasses are best planted in the southern part of the country. 2) They grow vigorously in the summer months, and turn brown in cold weather. 3) Warm-season grasses include Bermuda grass, St. Augustine grass, and zoysia grass. c. Climate Zones: Besides seasonal temperature, the success of any given turfgrass also depends on factors such as precipitation, humidity, soil pH, and altitude. A number of climate zones can be identified based on these factors. Some of the climate zones can be described as follows: 1) Cool and Humid: a) This zone includes the Pacific Northwest, west of the Cascade Mountains. b) The area has high rainfall and acid soil. c) It is an excellent area for cool-season grasses. 2) Cold Winters and Summer Rains: a) The midwestern U.S. makes up this zone. b) The area has moderate soil pH and warm, humid summers. c) Cool-season grasses predominate here. 3) Hot and Humid: a) This is represented by the inland portions of the southern states. b) Rainfall is high, winters less harsh, and summers are humid. c) Warm-season grasses perform well here. 4) Variable: a) This transition zone between north and south, including most of California, has a variety of conditions depending largely on microclimate. b) Both warm- and cool-season grasses can be grown, but they sometimes require extra attention to look good. c) Careful attention must be paid to turf selection in these areas since the climate is ideal for neither cool- nor warm-season grasses. For more specific information on climate zones consult ALL ABOUT LAWNS (Ortho Books, 1985) 2. Turfgrass Characteristics: There is no one "best" turfgrass. Different species display various characteristics which must be balanced off against each other when selecting a turfgrass. The best choice for a particular application depends on the functions the turf will perform in addition to climate, light, use patterns, and resources for maintenance. The most important of these factors are described below: a. Temperature Tolerance: 1) Some grasses, such as Kentucky bluegrass, grow poorly in hot weather. 2) Some, like common Bermuda grass, turn brown when it gets cold. b. Drought Tolerance: 1) As water gets more scarce, drought-tolerant species such as tall fescue find more use. 2) Water-hungry types, such as perennial ryegrass, require more frequent irrigation. c. Tolerance of Low Mowing: 1) Frequent and low mowing are sometimes necessary, especially when turf is used for certain types of recreation. 2) Creeping bent grasses and improved Bermuda grasses are excellent for these situations, performing well from 1/4" to 1" in height. 3) Tall fescue and St. Augustine grass need to remain 2" to 3" inches long. d. Fertilizer Needs: 1) Tall fescue and zoysia grass can get by with little fertilization, a desirable trait in low-maintenance or droughty landscapes. 2) Bermuda grass and creeping bent grass need regular fertilizing to look their best. e. Shade Tolerance: 1) Often in smaller or residential lawns, shade tolerance is an important trait, especially if there are trees planted in the lawn. 2) St. Augustine grass and tall fescue are fairly shade tolerant. 3) Bermuda grass and Kentucky bluegrass have poor shade tolerance. 4) Basically, lawns perform poorly in shade, and should not be planted where there is less than 4 hours of direct sun every day. f. Tolerance of Traffic and Wear: 1) This is a critical factor for lawns that are used for play areas or sports activities. 2) Improved Bermuda grass and tall fescue are tough, resilient grasses. 3) Dichondra and creeping bent grass, in contrast, can take little rough treatment without showing damage. g. Off-Season Color: 1) Whether dormant in the winter, or slow-growing in the summer, no grass looks its best all year. 2) Grasses that hold their color well are desirable for most ornamental applications. 3) Common Bermuda grass is a poor performer in this regard, while Kentucky bluegrass tends to look good more of the year around. h. Disease Resistance: 1) Some grasses, such as creeping bent grass and older strains of Kentucky bluegrass, are more likely to develop diseases such as rust and leaf spot. 2) Such diseases are much more likely to take hold if cultural conditions such as inadequate mowing and lack of water or fertilizer are contributing to turf stress. 3) Tall fescue and common Bermuda grass are relatively disease-resistant. 4) If turf is likely to be neglected, disease resistance should be a high priority in choosing a grass. i. Texture: 1) For ornamental appeal, a fine-textured lawn is most desirable. 2) Fine-textured species include creeping bent grass, zoysia grass, and creeping red fescue. 3) Coarse-textured turfgrasses, more functional than attractive, include tall fescue and St. Augustine grass. 3. Turfgrass Species: Below are briefly described 10 common grasses used for turf, divided into cool-season and warm-season types. Some of the advantages and disadvantages of each are listed. For more detailed information on specific turfgrasses, consult ALL ABOUT LAWNS (Ortho Books, 1985) pages 8-18. a. Cool-Season Grasses: 1) Creeping Bent Grass: Used for putting greens, bowling greens, and other highly-manicured areas. a) Advantages: Fine texture, low mowing height. b) Disadvantages: Disease susceptible, needs lots of water and fertilizer. Frequent mowing is costly. 2) Kentucky Bluegrass: Classic choice for ornamental lawns. a) Advantages: Rich, blue-green color, easy to grow in cool-season climates, newer varieties disease resistant. b) Disadvantages: Takes lots of fertilizer, dethatching. High water requirement, performs poorly in heat. 3) Hard Fescue: Used in turfgrass mixes for shady areas. a) Advantages: Good tolerance to heat, drought, and shade. Resistant to diseases. b) Disadvantages: Slow to establish. 4) Creeping Red Fescue: Common ingredient in bluegrass mixes. a) Advantages: Blends well, takes shade and drought. Deep green color and fine texture. b) Disadvantages: Susceptible to summer diseases, poor tolerance to traffic. 5) Tall Fescue: Great for play areas and low-maintenance turf. a) Advantages: Low water and fertilizer needs, pest resistant, takes wear and tear, fairly shade tolerant. b) Disadvantages: Coarse texture, clumps if not uniformly sown. 6) Perennial Ryegrass: Also used in bluegrass/fescue mixes. a) Advantages: Fast germination and establishment, good wear resistance, fine texture. b) Disadvantages: Cold sensitive compared to other cool season grasses, needs a lot of water. b. Warm-Season Grasses: 1) Common Bermuda Grass: A widely adapted grass, considered in many places a noxious weed. a) Advantages: Takes wear and abuse, tolerates heat, drought tolerant. Low maintenance. b) Disadvantages: Invasive, both by seeds and stolons. Won't take shade, turns brown in the cool season. 2) Dichondra: Not truly a grass, but a low-growing, broadleaf ground cover which is nonetheless used like turfgrass. a) Advantages: Low growing, attractive texture, requires little mowing. b) Disadvantages: Takes little or no wear, requires a lot of water and fertilizer, broadleaf weeds are difficult to control, and insects like it. High maintenance item. 3) St. Augustine Grass: A problem-solver in seaside conditions. a) Advantages: Tolerates salty soil and shady conditions. Vigorous and fast-growing. b) Disadvantages: Needs a lot of water and fertilizer, requires frequent dethatching. Intolerant of heavy traffic. 4) Zoysia Grass: Performs well in the southern states. a) Advantages: Fine-textured and dense, takes heat, drought and wear, fairly pest free, and has low water and fertilizer requirements. b) Disadvantages: Slow to establish. Can build thatch quickly. 4. Turfgrass Blends: Most frequently, turfgrasses are planted in mixtures, rather than as one kind of grass alone. a. It is important to remember that there are many different cultivars of most of the above listed turfgrass species, each having its own strengths and weaknesses. b. Most often, these cultivars are blended to balance the desirable and less desirable characteristics of each cultivar. This makes the resulting turf more able to resist disease problems and environmental changes. When one cultivar is having difficulty thriving, another one in the blend will find conditions more to its liking. c. Different SPECIES are blended as well, such as the bluegrass/red fescue/perennial rye mix mentioned above. C. Installation of Turf: 1. Site Preparation: Regardless of the method used to establish turf, the planting bed must be well prepared if a healthy, even stand of turfgrass is to be expected. No amount of water, fertilizer, or pest control, applied after turf is planted, will correct problems related to poor installation practices. Time and effort spent on preparing the site initially will more than pay for itself in reduced long-term maintenance costs. Following are seven basic steps required to properly prepare for a turfgrass planting: a. Rough Grade: Before doing anything to improve the soil for planting, all grading that will change the land form must be accomplished. 1) If berms or swales are to be part of the design, these should be formed at the earliest stage. 2) Surface drainage should be considered at this time, moving earth so the turf will drain evenly away from structures and pathways. 3) If grading will involve deep excavation, topsoil should be removed and reserved off to the side. When most of the grading is accomplished, the topsoil should be replaced so the turf will have the benefit of a better soil. b. Soil Test: When the rough grade is established, the native soil should be tested to see what amendments, if any, need to be mixed with the soil before planting. 1) Testing soil is an important investment in the landscape. Soil is the most influential factor in growing healthy turf. Since correcting soil problems is difficult or impossible once the turfgrass is planted, it is wise to find out exactly what needs to be done ahead of time to provide the best growing medium possible for the turf. 2) Nutrient status should be tested for, so the correct fertilizers and nutrients can be added as necessary. 3) Textural analysis should be conducted to determine if amendments will be necessary to compensate for textural deficiencies. 4) pH and EC tests should be conducted to determine if acid or alkaline conditions need to be corrected or if the soil is too salty. 5) Testing and analysis should be done by a reliable laboratory. Most do-it-yourself soil testing kits are inadequate. 6) Take representative samples of the soil, and handle samples in such a way that they are not contaminated. For detailed information on soil sampling, refer to (CLF333) Influence of Texture on Soil. c. Control Weeds: Weeds must not be allowed to compete with a turfgrass planting while it is getting started. A weed-free lawn, once established, will keep most weeds out on its own, with only occasional maintenance by the landscaper. 1) Old sod, if present, is considered a weed, and must be killed off and removed. Glyphosate (Roundup or Kleenup), a fumigant (methyl bromide or Vapam), or covering with black plastic for several weeks are all good methods of killing old turfgrass. 2) Weed control is particularly important if the lawn is being planted from seed. 3) Sod will smother weed seeds and seedlings, but deep-rooted perennials will come up through the turf. Use glyphosate or fumigants to kill perennials to their roots. This should be done early on, in case a second treatment is needed before planting. 4) If there are no perennials present, weed control can be postponed until further site work is complete, and any weed seeds which pose a threat are at the soil surface. d. Install Utilities: All underground utilities should be installed before soil is amended. 1) Any subsurface drain lines should be constructed, and necessary catch basins installed at the low points. 2) Sprinkler head locations should be established, and irrigation lines run. 3) Any 120 volt electrical lines should be laid. Even if electricity will not be used immediately, conduits should be run to avoid excavation problems later. Try to anticipate future utility needs. 4) Utilities should be set at depths complying with code requirements, and certainly deep enough so soil amending and mixing will not damage lines. Mark locations of lines and fixtures with scrap PVC pipe to help avoid damage. e. Amend Soil: Add soil amendments as recommended by the soil lab. (NOTE: Additional information on amending soil can be reviewed in topic plan (CLF6403) Managing Horticultural Soils.) 1) Correct Nutrients: a) Usually, nitrogen needs to be added in some quantity. b) The nitrogen present in steer manure or treated sawdust may be sufficient, or an inorganic source such as ammonium nitrate may be needed in some quantity. c) Follow, don't exceed, the lab's directions, or you will risk burning new roots. 2) Improve Texture with Organic Material: a) Often, nitrogen-treated redwood sawdust will be added to soil to help sandy soil hold more moisture, or to open up a clay soil for better drainage. b) If an organic amendment is called for, be sure to use enough. Usually, enough amendment should be incorporated to account for 1/4 to 1/3 of the soil volume after mixing. c) Skimping on materials leads to ineffectual amendment. 3) A high phosphorous fertilizer can be added to help the lawn thicken up quickly. 4) Correct pH: a) Lime can be used to raise pH if necessary. b) Calcium sulfate or other sulfur-based materials can be used to lower soil pH if needed. 5) Mix Amendments Evenly: a) When amending soils, spread the materials evenly, and mix thoroughly to a depth of at least six to eight inches. b) Be sure soil near the edges and around fixtures in the lawn area is mixed as well as that in the center. c) Excavate around these obstacles by hand if necessary, then backfill with amended soil. d) Uniformity of soil is a prerequisite for a uniform stand of turfgrass. f. Establish the Finished Grade: Prepare the soil surface for planting of seed or sod. 1) Rake the surface of the soil to an even grade, using a bow rake, a landscape rake, or a chain-link drag. Large turf plantings will require a tractor for this operation. 2) Remove as much debris and as many rocks as time allows. These prevent an even growth of turf. 3) Install sprinkler heads to the desired height at their final location. Remember to allow extra height if sod is to be planted instead of seed. 4) Lightly roll and water the area to help settle the soil. Rework the grade, if necessary, until an even surface is attained. g. Germinate Weed Seeds: Only if the turf is to be planted with seed, water the prepared ground to germinate weed seeds. Once germinated, these can be killed with a fast-degrading material such as glyphosate, or can be hoed LIGHTLY, to avoid bringing fresh weed seeds to the surface. 2. Planting Seed: Seed is an inexpensive way to plant a turf area, but there is more initial maintenance to perform. Also, seeded lawns need more time to become established before they can be used. To establish turf from seed: a. Use fresh, germination-tested seed. b. Rake: LIGHTLY rake the area to be sown, to slightly scarify the surface, and create spaces for the seed to fall in. c. Sow Seed: 1) Sow the seed using a fertilizer spreader. A "Whirlybird" or "Cyclone" type spreader works well. 2) Apply the seed in two or more passes, travelling at different angles. 3) This helps insure even distribution of the seed. d. Roll: 1) After the seed has been sown, roll the area with a heavy roller to put the seeds in firm contact with the soil. 2) This will insure their ability to take up water. e. Mulch: 1) Mulch over the seedbed with a fine-textured organic material. 2) The mulch will hold moisture, and keep seed from drying out. 3) Steer manure makes a superb mulch for this purpose. f. Water: 1) A new planting must receive frequent, short waterings; this is the opposite of what established turf needs. 2) Frequent waterings are needed because the shallow seedbed MUST NOT be allowed to dry out at any point until the seed has germinated and roots are established. 3) Waterings should be short, because the bare soil, with no vegetative cover, is prone to runoff and erosion. g. Protect the Planting: 1) Keep foot, animal and any other kind of traffic off of the planted area. 2) Put off the first mowing until the turf has "knit" well enough to take the weight of the mower and the operator without sinking or tearing. Make the first cut high if necessary, and then lower the mower. 3) Several weeks after germination, control broadleaf weeds by hand if possible, or with a chemical. 4) Giving a lawn extra attention during its first weeks of growth will pay dividends in saved effort later on. If there is no time available to see to a newly established lawn's needs, consider planting sod. 3. Laying Sod: Sod has the advantage of already being established, and requiring only to be correctly transplanted into place. Many professionals rely on sod for its fast, sure results. To establish a sod lawn: a. Check Grade: Make sure the soil has been graded around pavings and fixtures to allow for the 1/2" to 1" thickness of sod. The edges will dry out if sod is set above grade. b. Moisten Soil: Moisten soil a day before planting if the soil is dry. c. Unroll Sod Into Place: 1) Start along a straight border, if there is one. 2) Orient the strips of sod so they cross the main view axis in and out of the property, rather than run along it. This will help make the edges between strips less visible. 3) Stagger strips of sod in the manner of a bricklayer's pattern. This will minimize "stripes" showing up in the turf, and will give the lawn a more even look. Unroll each strip of sod in the same direction--sod has a "nap" that shows up when strips are laid in different directions. 4) Be careful to lay tightly rolled ends flat, and avoid overlapping ends. These will dry out and die. Also, avoid cutting small pieces of sod to patch in irregular areas. Small patches of sod tend to shrink and dry out. 5) Make sure all edges are butted up against each other tightly, to avoid dead sections between strips. d. Cut Sod to Fit: Cut the excess sod along curved edges and around sprinkler heads with a sharp linoleum knife. e. Roll the Sod: Use a water-filled roller to press the sod into contact with the soil below. As with seed, this will insure efficient water uptake from the soil, and will prevent sod roots from drying out. f. Water: Water sod thoroughly, irrigating on a daily basis until roots have taken hold. Keep a close eye on edges, which tend to dry out quickly. g. Protect the Planting: Keep traffic off sod for at least two weeks. Sod can be mowed as soon as it is well rooted, between two and three weeks after planting. Note: Sod should be delivered only when all preparations for installation are complete. It should then be planted immediately. Sod can survive rolled up for only a few days, less if the weather is hot. __________________________________________________________ ACTIVITY: 1. Have students prepare the soil for and plant a small sod lawn on the school grounds. __________________________________________________________ 4. Other Methods of Establishing Turf: a. Sprigs and Plugs: These vegetative methods are used for establishing many warm-season grasses. They are economical, but take more time than seeding or sodding to establish a turf. 1) Sprigging involves broadcasting stems of torn-up sod, much as seed would be spread. 2) Plugging requires planting small patches of intact sod, complete with soil attached. 3) Whichever method is used, the area must be kept weed free while waiting for the turfgrasses to fill in. b. Hydromulching: A relatively new method, this is usually used for large areas. 1) With hydromulching a slurry of ground-up paper or straw, seed, fertilizer, and water is sprayed through a hose onto a prepared seedbed. 2) Hydromulching (also called hydroseeding) speeds up the process of planting by seed, making it practical for larger areas. 3) Hydromulching requires special equipment for preparing and spraying the slurry. D. Turf Maintenance: Turf requires more care than any other type of ornamental planting in the landscape. By attending consistently to the following procedures, maintenance problems will be minimized, and a healthy, attractive stand of turf will result. 1. Irrigation: Water needs of turf vary with species and growing conditions, but basically, turf requires more water than any other part of the landscape. a. Frequency: Since turf uses so much water, it should be irrigated as infrequently as possible. Some guidelines follow: 1) Infrequent, deep irrigations encourage deep roots. This will help turfgrasses perform better in droughty conditions, and will save water overall. If turf can be watered every three days rather than every day, substantial water savings and a stronger stand of turf will result. 2) Establish a watering schedule based on when turf shows signs of needing water. A grayish-green cast to the leaves, and loss of resilience when walked on indicate the need for water. 3) Turf growing in sandy soil will have to be watered more frequently than turf growing in clay soils. 4) Actual water consumption will depend not only on species, but on temperature, humidity, day length, and health of the stand. Watering frequency will change as these factors change. 5) If the amount of water needed by a particular stand on a specific soil can be determined, the use of published evapotranspiration (ET) rates can make the job of knowing when to water much easier. 6) If a lawn is being highly fertilized, it will require more water. b. Quantity: Generally more water, applied less often, is the preferred pattern of irrigation. 1) Try to apply enough water to wet the soil to a depth of six to eight inches. (Test with a long screwdriver the evening after irrigating.) 2) If applying this much water results in runoff, apply the water in several short irrigation cycles, 30 minutes apart. This will be necessary with heavier soils high in clay. c. Methods: While many homeowners still use a hose and sprinkler to irrigate their lawns, professional landscapers use automated sprinkler systems almost exclusively. Refer to (CLF6453) Sprinkler Irrigation Systems and (CLF6704) Irrigation Design and Installation for information on systems for irrigating turf. 2. Mowing: Mowing is often thought of as a chore relating only to the neat appearance of a lawn, and as such can be put off to a more convenient time. This is not the case. Mowing is actually an important requirement for a lawn to stay thick and healthy, and if neglected will result in a diseased, weedy lawn. a. Frequency: Frequency of mowing depends on how fast the turf is growing. 1) The lawn should not be allowed to grow more than half- again its proper height before mowing. a) In other words, no more than one third of a grass blade should be removed with mowing. b) For example, if the recommended height for a turfgrass is 1 inch, it should be mowed before the grass height exceeds 1 1/2 inches. c) A 2-inch lawn should be cut before it exceeds 3 inches in length. 2) Practically speaking, the importance of mowing regularly is greater than mowing when the turf is at precisely the right height. a) In general, a once-per-week regime of mowing will take care of most lawns even in their fastest growing season. b) This can be changed to once every two or three weeks as the dormant season approaches, and lawn growth slows. c) Special, short lawns such as bent grass golf greens require more frequent mowing, often on a daily basis. b. Method: How a lawn is cut is as important as how regularly it is cut: 1) Height: Different grass species require different mowing heights. a) Kentucky bluegrass, tall fescue and St. Augustine grass are examples of grasses which should be kept tall, between two and three inches high. b) Turfgrasses which grow from horizontal stems such as bent grasses, Bermuda grasses and dichondra require close mowing to discourage fast build-up of thatch. Mowing heights of 1/4" to 1" are common for these grasses. c) If water is in short supply, keep turf longer. Shading the root zone keeps grass cooler. Likewise, shorter heights are permissible in winter. 2) Type of Mower: Whichever mower being is used, the importance of maintaining sharp blades cannot be over- emphasized; grass blades are damaged by dull blades. There are two major types of mowers: a) Rotary Mowers: These cut grass with a horizontal blade turning at high-speed. - Rotary mowers are versatile and adjust easily to different mowing heights. - They are best adapted to higher mowing heights; one inch is about the minimum. b) Reel Mowers: These cut grass with a scissors motion between a rotating blade and a sharp bed knife. - A well-maintained reel mower makes a cleaner cut than a rotary machine, but cannot be used for cutting down high grass or chores requiring mobility and power. - Reel mowers are well adapted for low mowing heights, and are the best choice for highly manicured turf such as bowling greens. 3) Managing Clippings: Clippings can either be collected, or left to decompose where cut. a) If clippings are caught and collected, the result is a cleaner, more manicured look. This is preferred for small, intensively managed landscapes. b) Collecting clippings on large-scale turf plantings is impractical. The benefit of leaving clippings in place is that nutrients are returned to the soil, and fertilizer requirements are reduced. Also, the problem of disposing of clippings is eliminated. c) Mowers adapted to mulch clippings, by chopping them into fine particles, are available on the market. These result in a cleaner-looking lawn where clippings are left, and faster decomposition. 3. Fertilizing: Turf has high fertilizer requirements compared to most ornamental plantings. Careful fertilizing is NECESSARY to keep turf healthy, but overfeeding can be as great a problem as underfeeding. a. Fertilizers: There are a wide variety of fertilizers to choose from. When deciding which to use, keep these basics in mind: 1) Nitrogen Fertilizers: Nitrogen is the nutrient most needed by turf. Nitrogen is used in large quantities, and it moves out of the root zone very easily. It must be replaced regularly. a) Fertilizers containing only nitrogen will meet most of a lawn's nutrient requirements and keep it looking green. b) Nitrogen should be added on a regular basis. Workable fertilizing regimes range between once every two weeks to once every three months during the active growing season, depending on soil, grass type, fertilizer type, and environmental considerations such as rainfall. 2) Complete Fertilizers: In addition to nitrogen, these contain phosphorous, potassium, and, depending on the type, other macro- and micro-nutrients. a) With most turf types, complete fertilizers need not be used at every fertilizing, but a twice-annual fertilizing with nutrients besides nitrogen will help turfgrass nutrition. b) More frequent use of complete fertilizers may be necessary with highly-leached soils. c) A 3:1:2 ratio between nitrogen, phosphorous, and potassium is often recommended for turf plantings. A 21-7-14 fertilizer would be an example of such a fertilizer. 3) Organic Fertilizers: Fertilizing lawns organically has advantages and disadvantages: a) Lower nutrient levels mean less chance of burning, and organic materials improve soil texture and humus content. b) Bulk, appearance, and smell are common objections to organics. Also, products such as manures are often inconsistent in nutrient content. 4) Synthetic Fertilizers: While synthetic fertilizers require more frequent application, their ease of handling and predictability make them the most commonly used materials. Care should be taken to water these products in AFTER application. 5) Combination Products: Some fertilizers contain herbicides or insecticides in addition to plant nutrients. Care is required in their use. a) These can save time by applying two products at one time. b) Be certain the pesticide is needed, and needed at the same time and the same rate as the fertilizer. Otherwise, wasteful pollution of the environment is the main result. b. Fertilizer Rate: To know how much fertilizer to use, over a year or in one fertilizing, many factors must be taken into consideration: 1) The amount of fertilizer required varies according to different grass types and the nitrogen content of the fertilizer. Calculate fertilizer needs with regard to the actual nitrogen present in the fertilizer. 2) The fertilizer rate must also take into account the frequency of fertilizing and the area covered. Fertility needs of lawns are usually expressed in pounds of nutrient per 1000 square feet per year. 3) As an example, a 3000 square foot bluegrass/ ryegrass/fescue lawn requiring 4 pounds of actual nitrogen per 1000 square feet per year (typical) might be fertilized with 10 pounds of ammonium sulfate (21-0-0) every two months. During the growing season applications would be heavier; during the dormant season, correspondingly lighter. 4) When in doubt, use LESS fertilizer. More can always be added, but too much fertilizer applied to a lawn at one time can burn the roots and kill the turf. c. When to Fertilize: 1) Cool-Season Grasses: Cool-season grasses grow faster in the spring and fall, and require greater applications of fertilizer during those times. 2) Warm-Season Grasses: Start fertilizing warm-season grasses with the first signs of growth in the spring, and continue, generally speaking, through September. d. Methods of Fertilizing: Fertilizers can be spread in solid or liquid form. 1) Broadcast Spreader: a) The most common method of fertilizing, a broadcast spreader will throw fertilizer prills evenly over a wide area. b) Sizes range from the popular hand-held "Whirleybird" type spreader for small lawns to power-driven "Cyclone" spreaders used for large playing fields. c) Broadcast spreaders are fast, requiring few passes over a lawn area, and can be used on rough ground if need be. 2) Drop Spreader: Designed for home use, these drop fertilizer directly from a hopper to the lawn below. They offer accurate rates of delivery, but must be used carefully to prevent "striping" of a lawn, where application either overlaps or is missed. 3) Sprayers: Used for applying fertilizers in liquid form, sprayers are ideal for small lawns where it is easy to estimate even application. 4. Pest Control: A well-maintained lawn will have few pest problems, but left uncontrolled, pests can ruin even the best of lawns. Four major categories of pests are discussed below: a. Weeds: Weed control in lawns differs from weed control in many other crops or plantings in that desirable plants (the turf) completely cover the ground around the weeds. This makes weeds harder to single out to get rid of. 1) Types of Weeds: For the purposes of weed control, weeds can be classified by two means: a) Annual weeds vs. perennial weeds: - Perennial weeds are the more difficult to eradicate since the parent plant lives on from year to year, spreading vegetatively in addition to spreading by seeds. Examples of difficult perennial weeds are Bermuda grass, English daisy, dandelion, and clover. To get rid of perennials, we have to kill the plant itself, in addition to stopping seedlings. - Annual weeds depend on seeds to live from year to year, with the parent plants dying at the end of the season. In mild climates some annuals will survive until the next season. Common annuals include annual bluegrass, crabgrass, spotted spurge, and bur clover. To get rid of annuals, we only have to keep the plant from reseeding, or kill the immature seedlings. b) Grasses vs. Broadleaves: - Grass weeds such as annual bluegrass and Bermuda grass are difficult to control sometimes because they share many biological traits with the turfgrasses they infest. - Broadleaf weeds include annuals such as mallow and knotweed, and perennials such as dandelion and dock. Broadleaf weeds differ from grasses from a physiological standpoint, and as such can be controlled with selective chemicals which act only on dicots. 2) Weed Control: a) By far, the best method of weed control is PREVENTION. - Keep neighboring weeds controlled to eliminate seed source. - Keep turf thick and healthy through regular watering, mowing, and fertilizing. Weeds will be excluded from well-kept turfgrass. - These steps will eliminate the need for most weed control. b) Hand Weeding: When the turf is small, or weeds are few and far between, hand control is a practical method. Use an asparagus weeder or narrow trowel to get the roots out, or weeds will come back even stronger. c) Chemical Control: This is necessary with large turf areas, or on lawns which have extensive weed problems. There are two categories of chemical control: - Pre-emergent control: In this case, a chemical is spread to form a thin layer at the soil surface. When a weed seedling emerges, it is killed by the chemical. This is the most effective way of keeping undesirable grasses out of grass lawns. - Post-emergent control: Post emergent control is used if weeds actually become established in the lawn. Weeds are sprayed directly with a chemical. Selective sprays such as 2-4-D have the benefit of killing broadleaf weeds without harming the turfgrass. Nonselective sprays such as glyphosate also kill surrounding grass, necessitating reseeding. b. Diseases: Turfgrasses are susceptible to a wide variety of diseases, most of which are fungus problems. 1) Some of the more common fungus diseases of turf include: a) Brown Patch: Large, irregular circular areas. A problem in excessive heat. b) Leaf Spot: Elongated circular spots on leaf blades. Cool, moist conditions favor leaf spot. c) Rust: Bright, rust-colored spores on grass blades; gives a rust-colored look to the lawn. Warm, moist conditions, and lack of fertilizer encourage rust. d) Powdery Mildew: Grey or white dusty patches on blades. Common in shady conditions. 2) Prevention: As with weed control, the most effective disease control is keeping a vigorous, well maintained turf in the first place. Some specific recommendations to keep disease out of a turf area follow: a) Use a grass type which is well suited for the climate and environmental conditions. b) Water deeply, and only when needed. Excessive moisture or soggy conditions encourage fungus. c) Fertilize according to the seasonal needs of the turf. A malnourished lawn will fall prey to disease. d) Mow at the proper height. e) Dethatch as needed. Thatch buildup robs moisture and nutrients from grass roots, and creates conditions favorable for fungus. 3) Control: A wide array of systemic and contact fungicides are available to treat an equally wide array of disease problems. For information on specific diseases and control measures, consult a local agricultural extension agent. c. Insects: Most insects inhabiting a lawn are either harmless or beneficial. However, some insects have the capability of ruining an entire lawn in one season, given favorable conditions. 1) Pest Types: Three groups of insect pests can be identified for the sake of control purposes: a) Insects that live on the leaves and feed on plant juices. Examples are spider mites, leafhoppers, cinchbugs, and greenbugs (aphids). b) Insects that live at the soil surface and feed on leaves. These are mostly caterpillar-like pests (Lepidopterous) and include armyworms, cutworms, and sod webworms. c) Organisms that live below the soil surface and feed on roots. These include grubs, wireworms, and nematodes. 2) Control: To control most insect pests follow these steps: a) Mow the lawn. b) Remove clippings. c) In the case of above-ground pests (groups "a" and "b" above) water the lawn heavily and allow leaves to dry out. d) Spray with an insecticide specifically registered for the pest involved. e) In the case of soil-inhabiting pests (group "c" above), water insecticide into soil. Otherwise, do not water for two full days. f) Fertilize lawn to aid in recovery. d. Mammals: Gophers and moles are among the most damaging of pests, and can be a real challenge to control. 1) Moles are insectivorous, and damage turf by burrowing just under the soil surface in search of food such as grubs and earthworms. A preferred method of control is the spear or harpoon trap, set directly above the mole run. 2) Gophers dig and excavate an extensive network of burrows, some of which extend deep below the surface. "Macabee" and box-type traps are the most effective means of control, but require digging up some turf to set traps. Poisons can be used, but great care must be taken in their application. 5. Aeration: Aerating the turf, or plugging, is the the process of removing soil cores from the turf, and opening the soil to more air and better water penetration. a. Turf areas used for athletic and recreational purposes are subject to compaction and require regular aeration. b. Even the effect of lawn-mowing machinery operating over turfgrass, especially if soil is wet, can cause compaction to damage the root environment. c. Aeration should be performed at least once a year on lawns that are subject to heavy traffic or abuse. 6. Dethatching: Thatch is a layer of slowly decomposing stems, dead roots, and debris that accumulates above the soil and below the living grass blades. The periodic removal of this material is necessary for the health of turfgrass. a. Thatch keeps water from reaching the root zone of the turf, increasing runoff, and boosting humidity around the leaves, a condition which encourages disease. b. For small areas of turf, a thatch rake will remove thatch effectively, but dethatching manually is hard work. c. A verticutter is a machine that removes thatch with sharp rotating vertical blades, and is the best way to remove thatch on all but the smallest lawns. d. Remove thatch before lawns begin their flush of seasonal growth. Cool season lawns can be dethatched in the early fall or spring. Warm season grasses, which are more prone to thatch buildup, should be dethatched annually in the spring before growth starts. 7. Balancing Maintenance Activities: An important principle to keep in mind in maintaining turfgrass is to balance maintenance activities. a. For example, if you water more, expect to supply more fertilizer, mow more often, and dethatch more frequently. b. If climate dictates slower growth, supplying less water and fertilizer will keep the lawn in balance, and help discourage disease. c. By keeping this principle in mind, effort and expense devoted to maintenance can be minimized and lawn vigor will be maximized. 1/7/91 MH/clh #%&C