   Cool Season Lawn Establishment - August 23, 2006 Jeff Schalau, County Director, Associate Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Lawns are often demonized by those wishing to conserve water in landscapes. However, small lawns can be strategically located and provide benefits such as reduced energy consumption (cooling effect), soil stabilization, and dust control. Of course, turf areas also require mowing, regular irrigation, seasonal fertilization, and periodic renovation. Pets also enjoy lawns. Cool season lawns are those which stay green year-round. Cool season grass species suitable for our area are blends which contain a mix of Kentucky bluegrass, perennial rye, and fine fescue, or pure tall fescue (select a fine-bladed turf-type). The cool season blend is finer textured and more lush, but requires slightly more irrigation. Tall fescue is often coarser in appearance, but is more drought resistant, especially when mowing height is high. If you are considering a new cool season lawn, then now is a good time to begin. Weeds should be controlled prior to soil preparation and planting. If bermudagrass or other perennial weeds are present, you will need to kill them with a glyphosate herbicide. This may require repeated applications. Soil should also be amended by tilling in nitrogen stabilized or composted organic matter and phosphorus fertilizer (0-46-0). Remove rocks and large roots, and then roughly grade to create gentle slopes that drain surface water away from structures. At this point, the irrigation system should be installed. A well-designed irrigation system with head-to-head coverage and an automatic timer is highly recommended for cool season lawns. If you are unsure of how to design and install the irrigation system, hire a reliable professional. Just prior to planting, apply 10 pounds of 10-10-10 fertilizer (or equivalent) per 1,000 square feet and lightly rake it in. Light rolling with a water-filled roller will indicate any low spots or other irregularities to the area. A proper final surface will be firm enough to prevent ruts made by seeding equipment but will be loose and crumbly so that seed easily can be raked into the top 1/4 inch of soil. Once these steps have been properly followed, you are ready to install a turf by seeding or sodding. Seeding is less expensive than sodding, but you will almost certainly have annual weeds that may be controlled using a selective herbicide such as 2, 4-D. Small areas can be seeded by hand. A rotary-type fertilizer spreader can be used in larger areas. Try to apply five to 10 seeds per square inch. Heavier seeding will promote weak, spindly seedlings and spotty establishment. Calibrate spreaders to supply half the amount of seed in one pass over the area. Divide the amount of seed to be sown into two groups. Spread the first group of seed. Then spread the second group at a right angle to the first group to get even coverage. Sodding has the advantage of almost immediate establishment, but its disadvantages are initial cost and the high amount of labor involved. Choose high-quality sod that is actively growing. Sod is perishable and should not remain on the pallet or stack for more than a few hours. The presence of mildew and distinct yellowing of the leaves is usually good evidence of reduced turf vigor from being stacked too long. To lay the sod, start with a straight edge such as a driveway or sidewalk. Unroll sod pieces tightly against each other, but don't overlap. Lay the pieces in a staggered, bricklike pattern. Using a sharp knife, cut pieces to fit curves or small areas. After the sod has been laid, roll it to ensure good contact with the soil. Be sure to water thoroughly, and water every day during dry, warm weather. Avoid soggy situations. Whether seeding or sodding, the first year is the most critical and proper attention to irrigation and fertilization are key to success. Allow the grass to grow to about twice the desired height before the first mowing and only remove 1/3 of the total height in any mowing (this is a critical rule of lawn mowing). During establishment, you will need to mow more frequently until the desired height is reached. Do not mow when soil is wet. A follow-up nitrogen application in November (10 pounds of 10-10-10 fertilizer) will likely be needed. During spring, half of this amount should be applied in April and May. You should never fertilize cool season lawns with nitrogen during summer. As you can see, establishing and caring for a cool season lawn involves work and proper care. The University of Arizona Cooperative Extension has publications and information on lawn establishment and maintenance. If you have questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at cottonwoodmg@yahoo.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |