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A Homeowner's Guide to Organic Lawn Care
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ORGANIC LAWN CARE Why Organic? High Cost of Synthetic Pesticides Effect on Humans and Pets Environmental Concerns How They Damage Your Lawn Organic Overview Healthy Soil Appropriate Plantings Thick, Deep-Rooted Grass Regular Maintenance Lowdown on Lawn History The New World: Golf & Games Parks and Suburbs Communism and Crabgrass Know Your Lawn Soil Water Grass Lawn Rehab (Planning) Starting Off Right The Future (What You Want) The Present (What You've Got) Lawn Rehab (Practice) Thatch Weeds Compaction Soil Amendments Overseeding Fertilizing Regular Maintenance Mowing Watering Weeding Seasonal Maintenance Whacking Weeds Aerate the Soil Trashing Thatch Amend the Soil Keep It Green: Fertilize Pets, Pests & Problems Dogs and the Perfect Lawn Pest Control: Guidelines Bugs & Thugs Moles Weed Control Diseases Alternatives to Grass Ornamental Grasses Shade Lovers Sun Lovers Low Water Ground Covers Under Pines -- Acid-Tolerant Starting a Lawn Grass Types & Methods Preparing the Site Preparing the Soil Planting Caring for New Lawns Switching from NitroLawn To Do List: Any Time of Year To Do List: Fall/Early Spring Using a Lawn Care Company Sites & Sources Books & Articles Websites  This site is brought to you by www.PlanetNatural.com |
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Starting a New Lawn When putting in a new lawn, some people take whatever falls in their laps (or lawns) first, without checking into it very carefully. And sometimes this works out just fine! But if your lawn is important to you, then take your time preparing the site and the soil, and choosing the grass itself.A careful customer will consider a number of criteria: climate, durability, appearance, cost, maintenance, and ease of installation. Each variety has its pros and cons. For instance, amongst warm-season grasses suitable in the south, buffalograss and blue grama have fine blades and need little or no irrigation, but they are fragile. They don't make great choices for the spot where you're setting up a badminton court. Kikuyugrass, on the other hand, resists wear, but has much broader leaves. On one set of comparisons, Zoysiagrass has the highest ranking for heat tolerance, but the lowest for establishment rate. Before you order sod or buy seed, therefore, think about what you value in a lawn, what it will be used for, and what conditions it will face. Do you care about color or texture? How much? Does the local soccer team gather at your house (i.e., lawn) on Saturday afternoons? Do you have a lot of trees? Is drought tolerance a make-or-break criterion for you? Your answers will help you and anyone you consult choose an appropriate grass. Just to get an idea of the range of criteria out there, take a look at the UC Davis grass comparison charts (PDF format), which include three items having to do with wear alone: Wear Resistance, Recovery from Moderate Wear, and Recovery from Severe Injury. Check also with your local U.S.D.A. Extension Agent, landscapers and nursery staff for advice on what type of grass will work best not just in your area, but for you. If you've admired a neighbor's lawn, ask him or her what grass they are using and how much maintenance it requires. Be sure to find out whether that maintenance is done by a lawn service and if so, whether it's an organic service or not. A lawn that looks great with four applications of synthetic fertilizer yearly (standard for many lawn services) and thrice-weekly watering may not do well on a more laid-back maintenance schedule. Choose Your Grass and Your MethodWarm Season Grass or Cool?If you live in Canada, or in what's inarguably the northern US, you'll need a cool season grass such as bluegrass, fescue, or rye. All of these -- and it's more than it may seem, since each is a family of grasses, not a single type -- grow best in spring and fall, going dormant and even brown in the summer unless it's watered. If you live in the south, you're in the area for warm season grasses, which grow most vigorously during the hottest part of the summer. The list of grass families for the south includes the four Bs (Bahai, Bentgrass, Bermuda, and Buffalo) as well as Centipede, St. Augustine, Zoysia, and others. Between these two areas lies the transition zone, a band that runs roughly from Virginia and North Carolina to Arkansas, curving gently south, then slightly north again as it passes through West Virginia, Tennessee, Kentucky, as well as southern Ohio, Indiana, Illinois, Missouri, and Kansas.  from The U.S. National Arboretum's page on Turfgrass. In this area, choosing a grass can be tricky, as it's often too cool in winter for warm-season grasses, and too warm in summer for cool-season types. Several grasses, including Kentucky bluegrass & perennial rye, can work in the coolest parts of this zone (in the north and east), while tall fescue works better in the south and west. However, in lower areas of Georgia, Alabama, and the Texas Panhandle, warm season grasses such as Zoysia can be successful. Often, a blend of grasses, or even a mixture of warm and cool season grasses works best, one species picking up where another leaves off. In other words, it's complicated. The particulars of location and elevation vary so much that it's important to do a bit of local research before investing in a grass. Grass Type: Bunch or Creeping? Perhaps one of the most important and basic decisions about grass is whether you want a creeping grass, which spreads through root shoots, or a bunch grass, which can only reproduce through seeds. This may sound profoundly uninteresting, but the choice may turn out to be important. Creeping grasses sends out shoots or runners from the roots, which then sprout new tufts of grass. Some produce rhizomes, which run underground, and some produce stolons, which lie on top of the ground. Some overenthusiastic types produce both. Bunch grasses only reproduce through seeds, though individual plants also increase in size as new tillers sprout around their circumferences. Despite their name, (another, similarly misleading term is "clump" grasses) these grasses do not necessarily grow in hummocks, and they won't automatically make a lumpy lawn. However, they do tend to spread more slowly than creeping grasses, so a lawn started from seed will take longer to get established than would a lawn started with a creeping grass. On the other hand, bunch grasses do not tend to invade flower beds and sidewalk cracks as aggressively as do creeping grasses. Creeping grasses, especially those with stolons, are also more prone to thatch build-up. Sod, Plugs, Sprigs, or Seeds? Just about everyone knows you can start a lawn with sod or seeds, but many people, especially those in northern states and provinces, have never heard of a third option, plugs, much less a fourth, sprigs. Plugs are tiny pieces of sod -- a clump of grass with roots and dirt still attached -- that, when planted at evenly spaced intervals on a lawn, will gradually fill in those spaces to make a smooth, complete surface. Sprigs are even smaller than plugs, being just what they sound like -- a small sprig of grass with its root runner. That runner (a rhizome or stolon) includes a couple of nodes that will develop roots below and shoots above, when they're in contact with dirt. Sod is of course the easiest lawn to establish, and the quickest. Just roll out those brown cylinders, exposing their lush green inner cores, and voila! an instant lawn. Well, not quite. Even sod needs to be pampered for the first few weeks. See Watering, below, for details. This method does have several advantages, though, over all the competitors: it gives a finished look immediately, and a finished product within weeks. Furthermore, since there's no bare dirt once the lawn is laid, there is also no place for weeds to get a purchase, so weed problems tend to be minimal. One of the biggest drawbacks of sod is that many grasses cannot be grown and cut for sod -- they just don't respond well to having their roots sliced and then being rolled up and hauled away on a truck. Of those that will tolerate this treatment, only a few may be available in an particular area. In general, only creeping grasses have been available as sod, because their rhizomes and stolons help them form a dense mat that will hold together under the stresses of cutting and transportation. However, some mixes are now available, including, for instance, mixes of Kentucky bluegrass (a rhizomous grass) with various fescues (mostly bunch grasses), which makes a more shade-tolerant mix than pure Kentucky. Seed costs far less than any other method, and sowing it takes less time than anything except laying sod. However, seed also takes longest to become established -- over a season for many grasses. This longer time period means that bare dirt is left exposed to weed seeds for several months, so weeds can be a bigger problem in seeded lawns than in sod lawns, particularly. However, seeding has gotten a bum rap where it perhaps doesn't deserve one, because the right seed mix will cover bare dirt quickly, creating a useable lawn earlier than one might expect and eliminating much of the weed problem. Learn more about establishing a lawn from seed here. Plugs have one important advantage over sod: they don't have to be planted at once. The grass blades in sod rolls get no light, and the weight of the roll itself compresses them, so it's important to minimize the amount of time they spend in the rolls. Lawn plugs, on the other hand, usually arrive in trays, each plug in its own little compartment. While it's best to plant them soon, plugs can be maintained for days or even weeks, as long as they're given adequate light and moisture. Since sprigs are smaller than plugs, more are needed to start a lawn in a reasonable amount of time, and since they don't travel with their own bits of dirt, they need to be tended more carefully and planted more quickly. They should be kept moist and shaded until they're in the ground. Only creeping grasses can be propagated with sprigs or plugs, as both methods depend on the root nodes that develop on creeping grass rhizomes and stolons to fill in the bare spaces between plantings. They take more time and energy to plant than grass seed, but will fill in more quickly. Plugs and sprigs can be ordered from grass companies, but they can also be "made" at home, if you have at least some creeping grass. Sprigs are produced simply by freeing lengths of root from sod. The trick is to avoid damaging them in the process. Soaking a piece of sod for an hour or two loosens the earth, making it much easier to find, follow, and remove individual root strands. They're most likely to be viable if the root sections measure at least six inches and if they include both some root and some grass blades. Only a few grasses can be propagated using all four of the methods described here. As mentioned above, some don't make a good sod, and bunch grasses can't be propagated as sprigs or plugs. Furthermore, many grasses, especially cultivars developed in the south, cannot be sown from seed. Since they are hybrids, their seeds do not run true and will not reliably reproduce the grass on which they grow. Zoysia, Bluegrass, Fescue, Buffalo, Rye, ... There are an enormous number of grasses out there, and more are being discovered, cultivated, and developed all the time. Within each family, three to a dozen different species may be available, and different cultivars of specific species also exist, each with slightly different disease resistance, water needs, and other characteristics. This article discusses the dominant characteristics of a number of grasses, but more complete lists are available in a number of places. Many state extension offices host a website giving advice about the best turf grasses for that state, but two of the most complete sites are those maintained by the University of California at Davis, and by the University of Illinois at Urbana-Champaign. Warm Season Grasses One of the best-known and oldest warm-season grasses, Bermuda grass, originated not in Bermuda but in the savannahs of Africa, where it serves as an important pasture grass, and where its deep roots allow it to survive drought. A tenacious grass blessed -- or cursed -- with both rhizomes and stolons, Bermudas form a dense sod that prevents erosion, requires little irrigation, and tolerates salt, thin soil, high traffic, and a wide range of pH values. Now considered a weed in many areas, Common Bermuda can be sown from seed, has relatively coarse blades, and can be quite problematic if it gets established where it's not wanted. Hybrid Bermudas, of which there are several, have been bred for finer blades and less invasive growth. However, they require more nitrogen and closer, more frequent mowing than Common Bermuda. Buffalo grass, perhaps the only warm-season grass native to North America, is becoming increasingly popular in arid areas, as it requires virtually no watering through the summer. It differs from most warm-season grasses in several ways. The first, generally considered a drawback, is that it will go brown in summer unless irrigated. The other two, considered advantages, are that it tolerates both shade and cold far better than do most warm-season grasses. Though not as resistant to wear as Bermuda grasses, Buffalo grass serves well in lawns that get ordinary use. St. Augustine, a broad-bladed grass that's quite common in the deep South, tolerates heat and shade but not cold or heavy traffic. Like Buffalo grass, therefore, it performs well in lawns but not in playing fields. Its dense growth, created by stolons, shuts out virtually all weeds but also causes a heavy layer of thatch, which can get so thick it impedes mowing. This grass therefore needs to be de-thatched on a regular basis. A number of cultivars of Zoysiagrass are available, with textures that range from fine to coarse. Propagated by both stolons and rhizomes, Zoysias form a dense, low, matted grass that needs little by way of water or nitrogen. Though it does not tolerate shade quite as well as St. Augustine, it wears better than that grass, and like it, tolerates heat and drought well. Cool Season Grasses Kentucky bluegrass is the traditional choice throughout cooler areas of North America, but its shallow roots mean that it requires considerably more water than do deeper-rooted grasses. In the rainier east where it was first introduced, this is not as much of an issue, but in the arid west, it is a real drawback. North of Colorado, fine fescues are becoming increasingly popular as lawn grasses. Native to the area, the fescues survive extremely cold winters; tolerate poor, alkaline soils heavy in clay; grow well in shade; and require very little fertilizer or water to remain green throughout the summer. Some top out at between six to nine inches, making mowing unnecessary in many locations. There are a number of types of fine fescue, including red, hard, and chewings, the "hard" here indicating "hardy." The hard variety of choice is generally "sheep" fescue (Fesutca ovina), the cultivar with the finest blades and slowest growth rate. Most fescues are bunch grasses; those that are not, such as red fescues, have relatively weak rhizomes, which do not bind turf into a dense sod as do the strongly rhizomous grasses. Partly for this reason, fescues do not stand up well under heavy wear, so they're better suited to lawns than to playing fields. Since they flourish in shade rather than sun, fine fescues are frequently mixed with Kentucky Bluegrass or other grasses either in a seed mix or in a sod. These mixtures, which make highly satisfactory, adaptable turf, also wear better than fescues do by themselves. Tall fescues have a coarser blade than the fine fescues and were originally used only as a pasture grass. Finer-bladed, slower-growing varieties are now available; these are widely grown as turf. Slow growth is preferable to avoid tufts of taller grass in the midst of a lawn. If you are buying tall fescue, be sure you're buying seed for a turf grass, not a pasture grass! The turf varieties tolerate more sun and warmer temperatures than do the fine fescues, making them a preferable grass in some areas. Two rye-grasses commonly appear in lawns. Annual ryegrass has two roles, the first of which is to provide color in southern lawns during the cool months. For this purpose, it is over-sown in the autumn as the warm-season grasses enter their dormant period. Its second role is to suppress weeds in newly seeded lawns. Since it germinates quickly but does not create a very dense canopy, it makes an ideal "nurse" crop for other, more slow-germinating grasses such as the fescues. Mixed with one or more fescues, it will create a complete ground cover in the first season but will then die back, leaving the field (or lawn) to the finer-bladed perennial grasses, which by then are well-established and able to hold their own against weeds. Perennial ryegrass, the most wear-tolerant of the cool-season grasses, requires more sunshine and water than the fine fescues, but emerges more quickly. Since it does not tolerate temperature extremes, it is particularly well-adapted to temperate coastal zones. Transition Grasses As mentioned above (warm season grass or cool?), the transition zone can be tricky. Since conditions in much of the zone don't really favor a particular grass, mixtures and blends are usually the best way to go. But conditions vary so much within the zone that an ideal mixture in one area may do poorly elsewhere. If you're in the north, or the east, or if you're at a high elevation, think cool grasses. If you're in the west, or the south, and at a low elevation, you'll probably need warm-season grasses. It all depends. Consult your local extension agent. There's one in every county. Many states also have websites that discuss the best turfgrasses for that state. Mixture, Blend, or Monoculture? You may find yourself staring at a row of grass seeds with these terms printed on them, or a clerk may toss them over her shoulder as she leads the way towards the grass-seed section: Were you wanting a mixture or a blend, sir? Or was it a monoculture you were thinking of? Chances are, these questions will only raise more questions in your own mind. The first two terms in particular cause trouble because they're easily confused, so here's the low-down. Mixtures and blends both contain more than one type of grass seed, but where mixtures contain seeds from different species, blends contain seeds from different varieties or cultivars within the same species. The seeds in a blend, therefore, are closely related, while those in a mixture are not. A bag containing Kentucky bluegrass and red fescue would be a mixture, while one containing red fescue and hard fescue would be a blend. If you leave a seed store with a bag containing two cultivars of Kentucky Bluegrass, red, hard, and chewings fescue, and perennial ryegrass to top it off, you've got both a blend and a mixture in hand. To simplify, I'll refer to both mixtures and blends as mixes where it's not important to distinguish between them. A monoculture is a single strain, but the term is not always used strictly. For instance, a lawn of Kentucky bluegrass might be referred to as a monoculture even if it is actually a blend of several cultivars. As in so many things, the pendulum swings back and forth on whether a monoculture or some blend or mixture is "best." Most lawns in the first half of the 20th century were mixtures, even including clover, which is not a grass at all. As the cult of the perfect lawn grew in the fifties, first clover, then crabgrass, then dandelions were banned from the yard, and finally, the ideal of the perfect, absolutely uniform and unbroken sweep of grass took hold of householders' imaginations. This was the era of the monoculture. Gradually, people realized that these perfect, uniform lawns take far more time and money to maintain than do blends and mixtures, because like all monoculture crops, monoculture lawns are vulnerable to disease and pests. Mixtures and blends offer much better resistance to such problems, since what one variety in the mix succumbs to, another may tolerate. Mixes also tend to give better coverage in lawns that have any variety in shade, soil composition, or elevation, again because one variety may thrive where another struggles. In recent decades, therefore, mixtures and blends have come somewhat back into fashion, though it's still possible to find warnings against them. It's true that an uneven distribution of different grasses can give a patchy look, and poorly matched grasses may grow at different rates, creating such an unkempt appearance that even the aesthetically indifferent may draw back. However, a good mix of grasses should not have these problems. The closely related grasses in a blend look similar and grow at similar rates, so they should have nearly the same appearance as a monoculture, while offering greater disease and pest resistance, as well as adapting to a slightly wider range of growing conditions. The seeds in a mixture, too, can be chosen from grasses with similar appearances and growth rates, avoiding the disparities that result in shaggy or patchy-looking lawns. Moral: No one choice is "best" for all situations, uses, households, or lawns. Preparing the SiteWeed ControlThere are three basic types of weed control for use before establishing a new lawn: cultivation, herbicides, and solarization. All are covered in greater depth in the Weeds section of Lawn Rehab (Practice). Cultivation. In this context, "cultivation" is a synonym for "hoeing." The surprise here (perhaps) is the first step, which is to water, or to cultivate soon after a rain. Why encourage weed seeds to sprout by watering them? Because if you don't, they'll likely lie there in the soil unsprouted until it rains. If you water them, then dig them up after they sprout, they're gone. But since some seeds sprout later than others, a single pass with a hoe will not catch all offenders. Several rounds of irrigation followed several days to a week later by hoeing will catch a much greater percentage of offenders than would a single round. This tactic, repeated several times through the spring, will eliminate most annual weeds. Perennials, however, which generally have a more complete root structure, will need a longer-term treatment. The University of California at Davis (link found above) recommends letting the area dry out over the summer and making repeated passes to remove perennial vegetation. Since foliage feeds roots, cutting off the green part of the plant repeatedly will eventually kill even the most insistent, long-lived weed. Herbicides. Most organic herbicides work best in warm weather. Unlike 2-4D and other systemic herbicides, organics work only on the foliage; they are not carried into the root system of the plant. Therefore, on perennials with extensive root systems, repeated applications will be necessary. (Actually, this is true of chemical herbicides as well. A single application will kill the dandelions, but not a well-established stand of any weed with an extensive root system, such as kudzu, bindweed, or creeping bellflower. So you might as well go organic.) Solarization. This term refers to concentrating the sun's power to kill plants. Just cover the stand with black plastic -- not weed cloth, since that allows water through! -- tack it down, and wait. For ordinary weeds (nothing worse than big dandelions) a couple of weeks will suffice. Weeds with major root systems take longer, up to two months. The plants beneath the plastic are cut off from both light nor water, and are subjected to intense heat. The combination kills most weeds outright and will weaken all. Read more about using soil solarization to get rid of weeds here. Killing or Removing Existing Sod Overseeding lawns and slice-seeding will allow you to mix grasses, and if your care and maintenance program favors the new grass over the old one, the new will gradually replace the old. However, if you want to replace one type of grass with another completely and quickly, then the first step is to kill the existing sod. This can be done either by digging it up or by killing it in place. Note: Rototilling a standing lawn will not kill it, especially if it is planted with a creeping grass. The chunks of sod will just start growing again. Digging it up, or sod busting, is quick but exhausting. The Complete Idiot's Guide to Edible Gardening calls it "Heavy Lifting," while HGTV ("Sod Busting") describes it as "backbreaking." Between them, these two sources cover tools, techniques, and essential preparation such as soaking the sod thoroughly several days in advance. (Why make a hard job harder?) Before killing sod, mow the grass as short as possible and give it a good stiff raking with a garden rake (not a leaf rake). On thatch layers so thick that raking is nearly impossible, quit for now and do this step after the grass is dead, when at least some of the thatch will have decayed. Rake up all the loose stuff; this is one time you don't want to let the grass clippings lie. Now that your lawn is scraped and shorn, it's ready for the final blow. You could skip this mow and de-thatch stage, but you'd have much more of a mess to contend with later. One of the simplest ways to kill sod in place using organic methods is to cover it with newspaper for several months. Warning: even this can be surprisingly tiring, and it requires A LOT of newspaper. Every square inch of the selected sod should be covered by a layer of newspaper about ten to twenty pages thick, and the layers need to overlap, and to be secured in place. Boards, bricks, stones, or staples can be used to hold the papers down, but the preferred material is a mulch or more dirt. These organic materials will cover the papers completely (no stray corner lifting with the wind), which speeds both the death of the sod and the decomposition of the papers themselves. As soon as you get the yard covered, water it thoroughly. A lawn covered by paper in fall will be "nice and dead" by spring, as Daria Price Bowman and Carl A. Price so appealingly put it in the Idiot's Guide. Furthermore, it now has a marvelous mulch on it, consisting of partially decomposed newspaper and whatever was laid on top of that. This method is ideal for spring planting. If you plan on rototilling, dethatching further is probably not necessary (nor is removing the newspaper). However, if rototilling is not on the agenda, then dethatching remains a higher priority, which means that newspaper may not be the best approach. Plastic laid down during warmer weather will also kill whatever is under it; this method therefore works especially well in summer, in preparation for fall planting. A lawn killed this way lacks the lovely mulch created through the newspaper method, but the old thatch is still on top and in view, ready for the rake. Drainage Issues -- Grading If you're lucky, you'll hardly have to think about drainage issues, and if you're really really lucky, you won't have do anything about them. However, not thinking about them at all is a mistake, as could become painfully clear while you sort through the sodden possessions in your basement. All surfaces should slope away from buildings and structures. A slope of at least two degrees (half an inch per foot) is generally recommended. If your lawn slopes towards your house, it would be wise to consider shifting some soil, installing French drains, or hiring a landscaper. Deep Grading -- Clay Subsurfaces Clay causes major drainage problems because it neither absorbs nor releases water easily. This is the opposite of "easy come, easy go." One of the worst situations a homeowner can face is a clay layer several inches or feet below ground level (a subsurface) that slopes towards the house, barn, or other structure. Water will permeate the top layer of soil, hit the clay, and trickle downhill on it (still underground) as if over a slab of cement, towards that structure. The surrounding soil can become completely waterlogged, making surface drainage a moot point. In bad enough cases, these sub-surfaces need to be exposed and graded to protect structures. This is a major landscaping project that usually requires machinery and professional help. However, before taking drastic (and expensive) action, consider trying a French Drain, below. Building Sinks in Low Areas Most grasses do not do well in low, soggy areas, so if your lawn sports one or more "mini-bogs," building a drain will help grass thrive there. Basically a shallow "well" filled with pebbles or sand, the drain or "sink" provides a place where water can collect, so that soil that usually remains sodden can dry out. French Drains Consisting of gravel-filled ditches that run downhill, French drains seem almost too simple to save a home or even a lawn or garden, but they can. The gravel allows for the free flow of surprising quantities of water, so these covered ditches, often no more than five or six inches wide, can drain wet areas or deflect water from vulnerable sites (such as your basement). Basically, installing French drains involves digging ditches from the wet areas down to some lower point where the water can be allowed to flow. (Not the neighbor's yard!) The ditches are filled with 1" gravel and topped with sand or sod. In a more thorough version, a lining and "roof" of weed-cloth ensures that soil doesn't clog the ditches. Some sites recommend laying perforated pipe, with the holes down, in the ditches on top of a layer of gravel. The pipes allow for completely unobstructed water flow. One of the trickiest problems, that of ensuring that the pipes drop at the appropriate rate (6-12" per 100'), receives a neat solution at the hands of David Beaulieu, writing for the Landscaping division of About.com. Beaulieu recommends driving two stakes into the soil along the line the drain will follow and some distance apart. Tie a string between them, using a string level to ensure that the string itself doesn't slope. If the ground between the stakes is uneven, you'll need tall stakes so the string can clear obstacles. Digging from the upper stake to the lower one, you can measure the drop on the lower stake. Between two stakes set 25' apart, for instance, the ground should drop at least 3", though 6" would be better. Be sure you have an even slope for the length of the drain. Note: French drains installed around a house should be set several feet away from the foundation, so that the soil near it is not allowed to become completely saturated. Grading the Topsoil In the absence of serious grading issues, topsoil is all you'll have to deal with. Even so, shifting significant amounts of dirt needs to be done before actual soil preparation. If you change the slope of the yard after adding amendments, you risk having two feet of expensive, amended topsoil near your house, and only an inch ten yards away. That's a waste, and it defeats the purpose of amending the soil at all. Preparing the SoilA new lawn planted on poor or poorly prepared soil may look good for a season, but after that it's bound to be a disappointment. People who skimp on preparation either find themselves pouring money into the new lawn, or they give up on it. Neither is an especially satisfactory result. And in case you were hoping that sod would be an exception to this rule -- it isn't. Sod arrives with an inch or two of soil, no more, and grass roots grow to at least six inches, so sod is not a system complete unto itself, but merely the starter. The deeper roots grow, the healthier the grass will be and the less water you'll need to keep it that way. And the better the soil, the deeper the roots will grow. So sod, too, needs to be laid on carefully prepared soil if it is to thrive.At least three soil criteria need to be considered: pH, nutrient value, and soil structure. The first of these, the pH, is of course the measure of soil alkalinity or acidity. This value helps determine whether plants will be able to absorb the nutrients in the soil, so it is an extremely important variable. The nutrient value of the soil will determine whether you will need to add fertilizer, and if so in what quantities. Finally, soil structure determines the movement of air and water in the soil, and like pH, influences whether and how easily plants can actually use the nutrients present in it. Test Soil; Adjust pH It's always best to get a soil test before making a major landscaping change, so that you can be sure you know what your soil actually needs. Home-use pH kits can be purchased at any garden store and many hardware stores, but a more reliable, complete soil test is available from many companies for a surprisingly low fee -- well under fifty dollars. Once you know your pH, you can adjust it, using any of several organic supplements. While most grasses prefer a slightly acidic soil of 6 to 6.5, even grasses differ slightly, and the start of a new lawn gives you the rare chance to set the pH precisely to suit the particular grass you plan to plant. (For details on soil amendments, visit Long-Term Lawn Rehabilitation on this site.) Add Topsoil, Amendments, and Fertilizer First, a quick review. While fertilizer adds nutrients to soil, amendments influence such things as drainage, air movement, soil structure, and compaction. In North America, fertilizers tend to be over-used, with the result that the excess ends up polluting our air and our waterways. Amendments, on the other hand, get short shrift. Householders can save considerably on fertilizers if they apply appropriate amounts and if they improve their soil with amendments before planting. The key amendment, always, is compost, but other organic additions such as cocoanut coir and sphagnum peat moss also improve soils significantly. All of these add organic matter, which breaks up clods in clayey soils, speeding drainage, and binds granules in sandy soils, slowing drainage. Organic matter also adds and nurtures the microorganisms which do much of the important work in soils, ensuring that they stay healthy. Other rock-based amendments such as lime may also be called for, depending on conditions. Slow-release organic fertilizers can also be added to the soil at this stage If you plan to lay sod, or plant plugs or sprigs, corn gluten meal makes an excellent choice. High in nitrogen, the primary nutrient needed by grass, it also suppresses seeds, so it acts as a pre-emergent herbicide. This can be a real plus in new lawns planted with plugs, where a lot of earth remains bare. Warning: Corn gluten meal will kill grass seeds as easily as weed seeds, though, so it is the worst possible choice for someone starting a lawn from seed. Finally, soil itself can be added, of course. Even a thin layer of new soil can do much to improve the scraped, compacted dirt left behind after a new home is built, or to alleviate the severe compaction of an old lawn now being renovated. Rototill, Aerate, or "Dig Like the Dickens" Deep cultivation, whether through rototilling or vigorous hand digging, remains the best preparation for any kind of new lawn. This step loosens the dirt already in place, incorporates amendments and fertilizer, and mixes soils. If only topsoil has been added, you would think this intense cultivation unnecessary, since the new soil hasn't been compacted. But using a rototiller (or deep digging) does more than relieve compaction: it also mixes dirt layers. Sharp divisions between soil layers, especially between new and old soils, can retard plant growth. So while there's a strong temptation to keep the beautiful, pristine topsoil separate from the greyer old soil beneath it, mixing often creates a better soil and a better lawn. If deep cultivation is beyond your budget or energy level, aeration is the next best choice. This job can be done with a hand tool or rented equipment, or it can be hired out. A gardening fork driven into the soil over and over is not nearly as good as aerating, since it doesn't actually remove plugs of soil, but it's definitely better than nothing. The more thoroughly the ground is aerated, the better. Don't worry about all those soil cores scattered over your "lawn"; they'll be re-incorporated into the soil sooner than you might think. Once the site has been aerated, sprinkle over it whatever amendments, fertilizers, and new soil you're adding, and rake to mix the soil plugs into this new layer. Doing so will accomplish some of the mixing of layers that deep cultivation achieves. If you do plan on deep cultivation, spread the fertilizers, amendments, and new soil over the planting area, then rototill or dig them into the dirt beneath, going back over the ground several times in different directions in order to break up earth clods and distribute all additions evenly. Don't try this when the soil is saturated; it'll be nearly impossible, for one thing, and it tends to create heavy lumps of earth, rather than stirring ingredients evenly. All cultivation disturbs soil structure in the short term, but the addition of organic amendments, in particular, will improve it in the long run. Once a healthy soil with good soil structure, is established, compost sprinkled on top of it will be incorporated into it by earthworms, making rototilling unnecessary -- which is good news for lawns. Harrow or Rake Unfortunately, rototilling often leaves soil in a unacceptably cloddy state. Harrowing breaks up these clods, helping to create the fine texture that roots find easy to penetrate. Harrows suitable for home use can be bought, rented -- or built. The simplest model for a lawn harrow is a piece of 3x3 plywood studded with heavy-duty 4" long nails set 4" apart in a grid pattern. Drill holes in two corners, attach a long rope, and you're set to go. The problem may be that if the equipment isn't heavy enough, it will just ride up over clods. If it's too heavy, however, you won't be able to pull it. This homemade harrow can actually test whether your soil is ready for planting. If it doesn't work, then either your soil is too wet, or it's too clayey, meaning more amendments need to be added, or those that have been added haven't been mixed in thoroughly. Roll -- or Be Prepared to Lift and Fill Yes, believe it or not, the soil you've just loosened now needs to be compressed -- gently. Think of this as firming it, so that it doesn't develop lumps and pockets. Rollers can be rented, or someone can be hired to do the job. Use a light roller, especially on clay soils. The last thing the new lawn needs is to start its life on compacted soil. A site on which you've laid only a thin layer of amendments may not need rolling, at least if it hasn't been rototilled. If pockets do develop in a new lawn, they can be filled from beneath (dig up the sod over the dip and add new soil beneath it), while lumps can be removed in the same way. This sort of patchwork, however, is both labor-intensive and often unsatisfactory. Rake Smooth and Shape A leaf rake makes the perfect tool for this final step. It also scores the soil surface slightly, leaving little depressions perfect for catching seeds. To prepare a surface for sod, grade it slightly so that the soil is about 2" lower than cement paths or curbs where they meet. This will ensure that the edge of the sod will be hidden, and protected, by the cement lip. PlantingTimingWarm season grasses are best sown or planted in late spring. This allows time for their roots to become established before the advent of hot weather, which can so easily dry out young, shallow-rooted grass. Spring planting sets these species up for the summer, when they have their quickest growth. Cool season grasses, though, do best if planted in the late summer or early fall. These grasses store energy in their roots in the autumn; when spring comes that energy goes into growth. So while these grasses can be sown in spring, fall sowing lets the new lawn concentrate on roots in fall and green growth in spring, resulting in a dense, lush growth even in the first summer. Sod Sod rolls are a convenient way to transport grass, but they're not good for it, so lay sod immediately after it arrives. To avoid stressing the new grass, water the area it will cover just before you start unrolling the sod. If you're covering a large area, stop after you've covered about 25 square feet and water the patch you've just laid. Laying sod goes quickly, but it is not easy work. Rolls of sod are heavy and bulky, and once they're unrolled, they can be difficult to adjust. It's best to get it right the first time, fitting edges carefully together as each roll is opened. Start at one side of the space to be filled, not in the middle, so that at most one piece of sod will need to be sliced lengthwise, not two. Lay down different lengths in a brick-like pattern, cutting them to fit where necessary, but avoiding a long straight line across the yard where all the pieces end. Water the whole lawn as soon as it is covered. Watch a video on how to lay sod here. Plugs Since each individual plug needs to be planted, plugs are not known for being especially easy (see Planting with Plugs). Dig holes in a grid pattern at distances appropriate for the particular species you're working with. Water lightly, then plant the individual plugs, covering the roots with soil. Rolling the area lightly afterwards will level the ground and firm soil over the roots. Water immediately. Sprigs There are a couple of different methods for planting sprigs. They can be scattered over the ground and lightly covered with soil, or they can be laid in shallow trenches that run across the planting area at 12" intervals and covered. In either case, the soil should be rolled afterwards and then watered. Seed Turfgrass seed should be spread quite thickly, to ensure an even growth dense enough to crowd out weeds. Measure your lawn, so you know its square footage, and check how many pounds of seed you will need for the particular cultivar or mix you plan to use. This is not the place to scrimp. Once the ground is properly prepared, the trickiest thing about planting a new lawn from seed is making sure that the seed gets scattered evenly. Hoppers or drum seeders make this much easier than broadcasting by hand, though that too can be done successfully. Whatever the method, several passes should be made across the seeded area, in different directions. Grass seed should be worked into the soil lightly, to a depth of 1/8 to 1/4-inch. The home-made harrow described above will do this admirably, but on a small lawn, a leaf rake works nearly as well. It is easier to keep even weight and pressure with the harrow, and to avoid actually moving dirt. Caring for New LawnsWateringAll new lawns, including sod, should be watered immediately after planting, but sod will require a deeper watering as it is a thicker layer. Make sure this first watering penetrates the sod layer, reaching to the soil beneath it, so that the sod can begin binding to that soil. For the first two or three weeks after planting, keep the new lawn moist. Not drenched, not waterlogged, but damp. When half the exposed area (in any lawn but sod) begins to look dry, it is time to water. This can mean watering two or three times a day. Even sod lawns need frequent, light watering for the first two or three weeks. Sod looks like a complete grass, but it's not. After all, its roots have been chopped short and so have its leaves, so it is already under considerable stress. Inadequate watering can kill it. After about two weeks, depending on temperature, rainfall, and so on, begin to ease back towards one watering per day. Watch your grass closely during this period. If it looks limp or goes grayish, return to the more frequent watering schedule for a couple of days, then try pulling back again (see Wise Ways to Water Your Lawn). In the third or fourth week, skip a day's watering and see how the grass takes it. Gradually decrease the frequency of watering, while increasing the depth. This will help the grass develop deep, drought-resistant roots. To Mulch or Not to Mulch Sod does not need mulch, but a lawn established with seed, sprigs, or plugs can benefit from it. A light layer of seed-free straw or leaf mulch helps the soil retain moisture, which is important for any of these methods, but critical for seeds. Seeds must be damp to germinate, and if they dry out, they die. However, too heavy a layer of mulch crushes young seedlings or even smothers them, depriving them of light and oxygen. So if you do mulch, do it with a light hand. Some soil should be visible under the mulch. One or two bales of straw is plenty on a thousand square feet. The Row-Cover Alternative Row-covers do much the same work as mulches, but they create a perfectly even and nearly weightless cover. Even when wet, they will not crush grass, and because they are white and admit light, they eliminate the danger posed by too heavy a layer of mulch: light-starved grass. Yet they do an amazing job of retaining moisture. They thus lower water loss -- and water use -- during the early weeks of a lawn's life. Be sure when you water, however, you're watering more than the cloth over the new grass. Check that the water is reaching the soil under the row-cover. When to Mow Newly seeded lawns, and those established from sprigs, can be mowed when the new grass is about three inches long. Be sure to mow when the grass blades are dry; mowing a new lawn when it's wet can actually tear clumps out of it. When to Walk By the time you can mow, a lawn is ready for light use. This is when you will finally begin to see the results of all that hard work. |
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