Responsible Lawn Care
By Catriona Tudor Erler
                Now is the time to get your lawn into shape for next spring and summer. But before you reach for the cheapest bag of lawn fertilizer and start spreading, it’s important to know what growing conditions favor a healthy lawn, and how to best achieve those conditions. 
Soil Quality
                The basis of a healthy lawn is its soil. Pests may annoy and weeds may try to intrude, but in most cases, if the grass is growing in good soil, it will be resilient enough to overcome these travails. To be strong and healthy, a lawn needs soil that is 6-8 inches deep, thus allowing room for good root growth.  As anyone who has gardened at Smith Mountain Lake knows, the native soil is not that deep, nor is the quality very good. Ideally fertile, loamy top soil should be imported, or the native soil needs to be amended to a minimum depth of 6 inches before you plant. You can improve the soil of existing lawns by annual core aeration and top dressing with well-rotted manure or compost. 
                Most lawn grasses flourish in soil with a pH range of 6.2 to 6.5, thus making more nutrients available to the plants. The best way to discover the soil pH is to have a soil analysis.  For $7,  the Virginia Cooperative Extension will do a comprehensive analysis, complete with a report telling what nutrients your soil needs. Once you send in the soil samples, you’ll get your report in about a week. If you have any questions when you receive your report, you can call your local Extension office. They will have a copy of the report and can help you interpret it. Here are the contact numbers for each local county: Bedford: 540-586-7675; Franklin: 540-483-5161; Pittsylvania: 434-432-7770. Follow the soil collection instructions carefully. The reliability of the soil test will be no better than the sample you submit. For results you can depend on, it is vitally important that you take samples correctly to accurately represent the soil in your lawn. 
Plant Suitable Grass Types
                Turf grasses are divided into two major categories: cool-season and warm-season.  At Smith Mountain Lake we straddle the warm- and cool-season zones. You can choose a warm-season grass such as Bermuda that will flourish in the heat of summer, or opt for a cool-season variety that will look a little tired when the weather gets very hot, but will thrive for most of the year.
                John Hamrick, an agent at the Franklin County Office of Virginia Cooperative Extension, recommends a cool-season mix of tall fescue, fine fescue, and Kentucky blue grasses.  The fescues are easy to establish, drought-tolerant, disease-resistant, hardy, durable, and tolerate compacted soil. They will green up early in spring, retire a bit during the summer heat, and then take off again when the weather cools in late summer.   
                It’s important to purchase grass seed from local suppliers because the seed mixes they stock will be well-suited to our area. It’s a false economy to try to save money by buying your grass seed in another state or bringing old seed from a previous home. The odds are good that the grasses in the mix will not do well in the Lake area.
                Don’t forget, grass is a sun-loving plant. In the wild you find it growing in open meadows where sunlight is plentiful. There are a few varieties bred to grow in some shade, but even these require at least a few hours of daily sunlight and do even better if the shade is relatively bright.  To improve the quality of shade for lawns, prune lower tree branches to allow more light.
Irrigation
                To stay strong and stress-free, grasses need one inch or more of water per week. To determine if your lawn needs supplemental water, pry back a corner of turf and insert a screwdriver or other sharp tool into the soil.  The tool should have moisture along the first 3 or 4 inches.  If not, you need to water.      
                You’re better off watering deeply and less frequently, rather than splashing on small amounts of water each day.  Deep watering will encourage deeper root growth and hence more drought tolerance.  If runoff is a problem before the water has soaked in enough, turn off the water as soon as you see the runoff  begin, wait 30 minutes to an hour, then restart the sprinkler in the same area.  Repeat as needed.
                Water early in the morning so the wet grass can dry before the sun becomes too strong.  The second-best time is early evening.  Less water is lost to evaporation at these times so more will reach the plants.         
Fertilizing
                Too little fertilizer leaves a lawn looking thin and weedy. Too much fertilizer also causes problems, making the lawn prone to thatch as well as insects and disease.  Proper fertilization leads to healthy lawns and reduces the chance of fertilizers leaching into our lake and groundwater. The ideal for the health of your lawn and your budget is to use the minimum amount of fertilizer necessary to keep the grass looking healthy and green.     
                Most people purchase the “balanced” lawn fertilizers available at garden centers. This approach can cost you more money than necessary and risk polluting the lake. These packaged blends are packed with nutrients your lawn may not need. For example, most lawn fertilizers contain 3 percent phosphorus. According to David Johnson, Professor of Chemistry and Environmental Science at Ferrum College, who has been monitoring the water quality of Smith Mountain Lake since 1985, the native soil at the lake has more than enough phosphorus to meet a lawn’s needs, and that nutrient is the primary culprit for promoting algae growth in the lake. So with these blended fertilizers you are spending money on ingredients the lawn doesn’t need and risking polluting the lake. 
                The best way to fertilize a lawn is with slow-release nitrogen. Homeowners who spread quick-release nitrogen in large quantities on their lawn for an instant rich, green effect are doing more damage than good. The lush leaf growth will occur at the expense of the roots, thus weakening the overall plant. In addition, those lawns will need much more frequent mowing. Your goal is to provide enough nutrients to encourage a strong root system that will support healthy top growth. 
                The quick-fix nitrogen fertilizers most commonly used are ammonium nitrate and ammonium sulfate. They are less expensive than the slower-acting fertilizers, making them attractive to budget-conscious gardeners. However, in the long run, they can be more costly. While the slow-release forms of nitrogen including sulfur-coated urea, urea formaldehyde, I.B.D.U, natural organic fertilizers such as Milorganite, and resin-coated urea are more expensive up front, they do not have to be applied as often. As a rule, lawns fed with a slow-release form of nitrogen have better color, thickness, and reduced leaf growth over lawns treated with quick-release nitrogen.
                Refer to your Cooperative Extension soil analysis report to find out exactly what nutrients your lawn requires, and then apply accordingly. The best time to feed a cool-season lawn such as fescue is in September, October, and November/December. Splitting the total yearly amount of fertilizer into three applications is best to minimize the potential for leaching.
                The advantages of fall fertilization for cool-season grasses are increased density, increased root growth, decreased spring mowing, improved fall to spring color, decreased weed problems, increased drought tolerance and decreased summer disease. Feeding at this time of year will help the lawn green up faster in the spring and make it more tolerant of heat and drought stress.
                In contrast, warm-season grasses, such as Bermuda and Zoysia, should be fed in spring and summer.
                An easy way to add extra organic nutrients to your lawn is to leave the clippings in place when you mow. Contrary to popular wisdom, these clippings do not build up a layer of thatch. If you mow before the grass gets too long so the clippings aren’t left in large clumps that block light to the grass, the clippings will decompose, adding organic matter to the soil as well as nutrients. A mulching mower is a great asset because it chops up the grass into little pieces that can decompose quickly. Grass clippings can reduce the need for fertilization by as much as 25 percent.  Decomposing grass clippings also encourage earthworms, which aerate the soil and add to the nutrient content with their castings. 
Weed Control
                The most effective method of controlling lawn weeds is to maintain a dense and vigorously growing turf cover. A weakened lawn, with or without bare patches, is the most common reason for increased weed presence. Killing the weeds without correcting the underlying problem will lead to unsatisfactory results. Control any annual weeds that intrude simply by mowing before they set seed. The plant will die at the end of its growth cycle. Perennial plants are more of a problem. If you have them in small quantities, hand weed the lawn.  Be sure to get the weeds out before they set seed, and work to remove the weed’s entire root system. It’s easier to hand weed when the soil is moist and soft.
                Another option is to use a fertilizer in early spring that is mixed with a pre-emergent weed killer. Be aware, however, that this is a non-selective herbicide. It will kill grass as well as weed seeds.
Mowing
                Many lawn problems are a result of cutting grass too short or cutting off too much of the blade at a time. Grass that is shorn too close becomes weak, enabling opportunistic weed species to compete more effectively. Close mowing also increases light penetration to the soil surface, which may encourage the germination of weed seeds. In addition, the grass is more likely to succumb to stresses caused by drought, insect injury, foot traffic, or too little sun. 
                Ideally you should never remove more than one-third of the leaf surface each time you mow.  The correct mowing height for fescues and Kentucky bluegrass is 3 inches. How often you need to mow will be determined by the lawn’s rate of growth. You’ll need to do the job more frequently in spring and fall when the grass is actively growing than in summer when it slows down. Most of the time a weekly schedule of mowing works well.      
                At least once a year you should sharpen your lawn mower blades. Blunt mower blades can ruin a lawn by tearing the leaves. Each torn blade will die back 1/8- to 1/4-inch, giving the lawn a brown tinge. The ragged edge on each blade of grass also makes the lawn more susceptible to disease.
                By improving the soil and following proper lawn care practices, you can have a beautiful, healthy lawn with a minimal use of polluting chemicals.

Catriona Tudor Erler is a freelance garden writer and photographer who divides her time between Smith Mountain Lake and Charlottesville, Virginia.  She is the author of eight garden books, including “Poolscaping: Gardening and Landscaping Around Your Swimming Pool and Spa,” “The Frugal Gardener: How to Have More Garden for Less Money,” and “Complete Home Landscaping.”