We have gathered the definitions of common lawn care terms, from abaxial to Zoysia. And we promise that this glossary will be more interesting than watching grass grow.

Abaxial
The abaxial surface of a leaf or grass blade is the lower surface, which faces away from the plant’s axis or stem. This side of the leaf is responsible for the exchange of gases, such as the absorption of carbon dioxide from the environment and the release of oxygen from photosynthesis. Because the abaxial surface reflects light differently than the upper or “adaxial” surface, mowing swaths of grass in opposing directions creates lawn stripes. See “How to Add Stripes to Your Lawn Like a Pro.”

Acidic soil
Also known as “sour soil,” acidic soil is soil with a pH of less than 7. The pH scale ranges from 0 to 14, with 7 marking neutral. Soil with a pH greater than 7 is known as alkaline soil. Soil pH influences the availability of essential plant nutrients, including those added through fertilizers. Optimal pH varies by plant type. Most grass varieties prefer slightly acidic soil, with a pH reading of 6.2 to 6.9.

Adaxial
The adaxial surface of a leaf or grass blade is the upper surface, which faces toward the axis or stem of the plant. This chlorophyll-rich upper leaf surface is responsible for capturing light needed for photosynthesis. Because the adaxial surface and the lower or “abaxial” leaf surface reflect light differently, mowing a lawn in opposing directions will create stripes in a lawn.

Aeration
Properly timed, aeration relieves compacted soil and encourages healthy grass growth. Essentially putting holes in your turf, aeration creates pathways that allow vital air, water and nutrients to penetrate thatch and compaction to reach grass roots. How often you aerate depends on the health of the lawn and how heavily it is used, but most lawns benefit from annual aeration. See “Your Guide to Lawn Aeration: When, Where, How.”

Agrostology
Agrostology is the branch of botany concerned with the study of grasses, especially their classification. From the Greek word “agrostis,” meaning “type of grass.”

Alkaline soil
Also known as “sweet soil,” alkaline soil is soil with a pH of greater than 7. Its opposite is acidic soil, which has a pH of less than 7. Soil pH ranges from 0 to 14, and most plants like soil somewhere near the neutral mark of 7. Alkaline soil is good for some plants and bad for others. Most grass varieties prefer slightly acidic soil.

Amendment
Soil amendments are added to or incorporated into soil to correct deficiencies and enhance its potential to support healthy plants. Amendments such as lime affect pH and nutrient availability. Other amendments, such as organic matter, improve soil structure and deliver nutrients.

Anaerobic
Anaerobic means lacking in oxygen. A soil structure that is anaerobic, typically due to poor drainage or soil compaction, will cause grasses and other plants to suffocate and eventually die. Aeration can help relieve soil compaction and improve air and water movement through anaerobic soil.

Annual grasses
Annual grasses naturally complete their life cycle in one year and then die, regardless of the growing zone. Annual grasses such as fast-rooting annual ryegrass are often used to stabilize and provide fast color to newly seeded lawns while slower-germinating perennial grasses take root.

Bahiagrass
This perennial, warm-season grass species is native to South America. Used extensively for agriculture, erosion and conservation programs, it is used as a lawn grass in areas of the Deep South, Gulf Coast and Southern California due to its tolerance for heat and drought. It likes full sunlight and low pH soils and spreads by short, stout, above-ground stems known as stolons. Easily recognizable when allowed to flower, it produces slender spikelets topped by V-shaped racemes.

Bentgrass
The carpet-like areas created by bentgrass have made it ideal for golf course greens in cool-season climates, but it is also sold as seed or sod for lawns. It spreads by above-ground runners (stolons). The three most common types are creeping, velvet and colonial, with creeping bent the most widely used for lawns and putting greens.

Bermudagrass
A leading grass for Southern lawns, Bermudagrass is a tropical native that requires full sunlight and well-drained soil. It has the fastest growth rate of any common warm-season lawn grass and spreads by both rhizomes and stolons. It is valued for outstanding tolerance to heat, drought, salt and humidity.

Biorational
Pest controls vary in their environmental impact and toxicity to people and other organisms. “Biorational” pesticides are those controls that are relatively non-toxic to humans and have low ecological risk beyond their intended target pest. Biorationals include plant-derived pesticides, such as neem oil, as well as bacteria-derived pesticides such as Bacillus thuringiensis (Bt).

Bluegrass (Kentucky)
Kentucky Bluegrass (KBG) is a vigorous, dense-growing, cool-season grass introduced to the United States by early European settlers. Praised for its rich green color, KBG thrives in full sun. It’s often mixed with more shade-tolerant grass types to bring superior color and texture to seed mixes for lawns with sun and shade.

Broadcast spreader
A broadcast or rotary spreader applies fertilizer, pesticide or seed in an imprecise, fanlike pattern over a broad area. In contrast, a drop spreader drops the substance straight down instead of scattering it, resulting in a precise application over a smaller area.

Brown patch
Brown patch is a common summer lawn disease caused by the fungus Rhizoctonia solani. It is treated with fungicide, but best prevented by good lawn management practices. For details, see “Fighting Brown Patch, Other Summer Lawn Fungus Diseases.”

Buffalograss
This warm-season, cold-hardy grass is native to North American prairies and savannahs. Named for the buffalo that once fed on it, it has become popular as a low-maintenance, natural lawn grass. Buffalograss naturally grows around 6 inches tall. It spreads by above-ground stems known as stolons. Male and female flowers typically, but not always, occur on separate plants.

Bunching grasses
Bunching grasses grow in clumps and spread by vertical shoots known as tillers, which grow from the crown of the plant. Unlike aggressive creeping grasses, they rarely have thatch problems. Common bunching lawn grasses include tall fescue and perennial ryegrass.

Calcitic limestone
Calcitic limestone is a type of pulverized limestone often applied to overly acidic lawns to raise soil pH and restore nutrient availability. Normal lawn care naturally lowers soil pH over time, but applying lime unnecessarily can harm grass instead of help. The only way to know for certain if your lawn or garden needs lime is by soil testing. Calcitic limestone contains calcium, but not magnesium — unlike dolomitic limestone, which contains both.

Carpetgrass
Carpetgrass is native to the Gulf Coast and tropics. Best adapted to the lower Southern states, this low-maintenance, warm-season grass creates a thick sod that crowds out weeds, tolerates dampness and shade, and covers slopes well. It requires frequent mowing if you want a seedhead-free appearance.

Centipedegrass
Centipedegrass is a slow-growing, light-green, low-maintenance grass species that spreads by sending out above-ground runners (stolons). A warm-season grass, it thrives in slightly acidic, sandy soil. Centipedegrass does not have a true winter dormancy period, so it’s susceptible to winterkill in areas with extended periods of low temperatures or extreme temperature fluctuations during spring.

Clippings
Lawn clippings are the portion of the grass cut off by a mower. Traditional advice was to bag and remove the clippings, which typically ended up in landfills. Turfgrass researchers now believe that mulching clippings and leaving them to decompose and add nutrients to the soil is better for most lawns. Due to environmental concerns, many states prohibit sending lawn clippings to landfills.

Clover
Varieties of clover, particularly white clover, were commonly sold in grass blends until after World War II, when chemical weed-killers were introduced that killed all broadleaf plants, including clover. The industry redefined clover as a weed, but it remains a key ingredient in seed mixes for erosion control. In recent years, clover has made a comeback as a ground cover. See “We’re Thinking Over Why We Kill Clover.”

Clumping
An undesirable mass of grass clippings that results from mowing a wet lawn, a poorly kept lawnmower or a repetitive mowing pattern. Grass clippings are a natural source of nutrients, but too much in one place can smother the living grass beneath it or encourage disease.

Cool-season grass
Cool-season grasses get their name because they experience their peak growth periods during cool spring and fall seasons. Most lawn grasses commonly used in northern states are non-native, cool-season types that can’t tolerate southern summers. These include spreading grasses such as Kentucky Bluegrass and bunching grasses such as tall fescue and perennial ryegrass. Cool-season grasses often go dormant during extreme heat and drought.

Creeping grasses
Grass types that spread by sending out horizontal stems are said to be creeping grasses. These grasses spread by above-ground stems called stolons, below-ground stems called rhizomes, or both. Examples of creeping grasses include cool-season Kentucky Bluegrass and warm-season Bermudagrass. Creeping grasses are more likely to have problematic thatch buildup than bunching grasses.

Crown
The crown of a grass plant is the all-important, whitish base where above-ground shoots and below-ground roots meet. When the crown sustains damage from improper mowing, disease or pests, the plant may die.

Culm
The culm is the stem of a grass or sedge plant. In most grasses, the culm is hollow between the nodes.

Cultivar
Cultivar is short for “cultivated variety,” meaning that humans intervene in some way to propagate or perpetuate the variety through cultivation. Grass cultivars may result from formal breeding programs or naturally occurring variations selected for some outstanding feature, such as drought tolerance, disease resistance, texture or color.

Cultural practices
In turfgrass, “cultural practices” refers to all the things that go into lawn care, including aeration, fertilization, overseeding, irrigation and, of course, mowing.

Curb appeal
In real estate parlance, curb appeal refers to whether a home’s outward appearance makes a good impression. A well-kept lawn can add to curb appeal, so it can increase the value of a house.

Desiccation
The drying out of grass plants, which can damage or kill them, is called desiccation. It can occur in summer droughts or during dry winters, when grasses dry out in the cold and wind. Improper mowing can increase desiccation, especially during times of environmental stress.

Dethatcher
A dethatcher is a tool used to remove thatch, the layer of organic matter that accumulates where grass meets soil. Dethatchers come in manual, electric and gas-powered models that remove thatch in a variety of ways.

Dethatching
Dethatching is the process of removing thatch from a lawn. Thatch less than ½-inch thick benefits your lawn, but a thicker thatch layer can harm it. Typically, only spreading grasses need dethatching; bunch-forming grasses do not. Proper timing is crucial for all dethatching projects. See “Dethatching Your Lawn – a Comprehensive Guide.”

Dichondra
Dichondra is a dense, warm-season, perennial ground cover. Well-adapted to moderate coastal climates, it is sometimes used as a grass alternative, but it doesn’t tolerate foot traffic well. It propagates from seed and spreads by runners. Mowing is optional. Dichondra does well in full sunlight and partial shade. It can be difficult to establish, but very low maintenance once mature.

Dollar spot
Dollar spot is a fungal lawn disease that, true to its name, appears as silver-dollar-sized spots on the grass. It can attack both warm-season and cool-season grasses. Dollar spot thrives from late spring to fall, and especially loves high humidity and temperatures in the low 80s. Causes include mowing too low, lack of fertilizer, excess thatch and overwatering.

Dolomitic limestone
Dolomitic limestone is a soil amendment used to raise soil pH in overly acidic lawns. Most lawn grasses do best in slightly acidic soil, where nutrients they need stay most available. Unlike calcitic limestone, which contains calcium, dolomitic limestone contains both calcium and magnesium. Magnesium is an essential plant nutrient, but too much can harm your lawn. Use dolomitic limestone to raise pH when a soil test reveals a magnesium deficiency as well.

Dormancy
Dormancy refers to a state where grass remains alive but not actively growing. Turfgrass can go dormant either in summer heat or winter cold. Warm-season lawn grasses naturally go dormant and turn brown during winter months. Cool-season lawn grasses may go dormant during summer heat and drought unless they receive supplemental irrigation.

Drought
In turfgrass terms, a drought is a prolonged period of dryness that may cause grass to wilt, go dormant and eventually turn brown. Without a reprieve, grasses may die. Grass varieties vary in their drought resistance and drought tolerance. See “Lawn Care Before, During and After a Drought” for details.

Edger
In lawn care, an edger is a tool used to give lawns a crisp, clean edge where it borders other plants or other surfaces. They can be manual or motorized. Also see “25 Things Every Lawn Enthusiast Should Keep in Their Storage Shed.”

Fertilizing
Fertilizing is the act of delivering nutrients to lawns and other plants. Lawns typically need fertilizers high in nitrogen for thick, green growth. More is not better. Too much fertilizer can injure grass and harm the environment. An increasing number of states and municipalities regulate phosphorus in lawn fertilizers because runoff leads to water pollution. See “Quick Guide to Lawn Fertilization” for more details.

Fescue
Fescues are cool-season grasses that thrive in the northern half of the United States. Tall fescues have greater heat tolerance than other common cool-season lawn grasses, making them excellent choices in the transition zone. Smaller-leaved fine fescues have exceptional shade tolerance. They’re an essential ingredient in seed mixes for dense shade areas and lawns with mixed sun and shade.

Fill dirt
Fill dirt is a boon for building contractors and the bane of gardeners. Typically low-quality dirt, it’s often used by contractors to fill in depressions and grade lots. Fill costs less than topsoil, but it generally consists of subsoil that lacks organic matter and beneficial microbes needed for healthy lawns and plants. It often contains rocks and other debris as well. Turning fill into healthy garden soil through soil amendments and good cultural practices can be a long, arduous process. See “Lawn, Landscape Tips for New and Remodeled Homes.”

Finishing mower
A finishing or grooming mower is a specialized lawn mower that gives a smooth, flat finish to an already well-maintained lawn. It generally has multiple blades capable of cutting lower than a standard mower. Because of its large size, a finishing mower is reserved for professional lawn contractors.

Flail mower
If the grass or brush is too thick for an ordinary lawn mower, it’s time to pull out the big gun of the grass-cutting world, the flail mower. Named for the blades or flails that spin, the flail mower is often made to attach to the rear hitch of a tractor. Flail mowers are an excellent choice for areas overgrown with tall grass, vines and brush.

Forage grass
Forage grasses are members of the grass family chiefly used for livestock grazing or “foraging.” Some popular lawn grasses have been developed from forage grasses.

Friable
Soil is said to be friable when it has the desirable consistency for healthy, uninhibited root growth. It is characterized by variable clods that crumble easily under pressure when moist. See “Friable Loam: The Ideal Lawn Soil and How to Get It.”

Fungicide
A lawn and garden fungicide is a type of pesticide designed to prevent, inhibit or control the spread of fungal plant diseases. Once active, many fungal diseases cannot be killed or controlled by fungicides. Fungal plant diseases are best managed through good cultural practices and proactive, preventive fungicide treatments.

Glabrous
Having a smooth, hairless surface. The term is often used in classifying grasses. Kentucky Bluegrass blades, for example, have a glabrous surface, which accentuates its rich green color.

Grass
There are about 10,000 species of grasses, of which 1,400 can be found in the United States. Grass plants are members of the Poaceae family of plants and vary greatly in size and growth habit. Some creeping bentgrass varieties naturally stay less than 3 inches tall, even without mowing. Some types of Giant Bamboo, also a grass, can grow as high as 150 feet tall.

Grasscycling
Grasscycling simply means leaving the grass clippings on the lawn after mowing instead of bagging and disposing of the clippings. The “recycled” clippings return nutrients to the soil, reducing the need for fertilization.

Grass pollen
Grass pollen is the male agent released by grass flowers as part of the fertilization process that leads to seed production. Grass pollen is borne by wind rather than insects. Because grass pollens are generally half the width of a human hair, the wind scatters grass pollen widely.

Grass pollen allergy
A common affliction that affects about 400 million people worldwide with symptoms that include runny noses, itchy throats and red, irritated eyes. See “Achoo! It’s Grass Pollen Allergy Season.”

Green roofs
Roofs planted with living material are green roofs, which are praised as a way to decrease utility costs while also trimming a building’s carbon footprint. See “The Dirt on Green Roofs” for details.

Growing degree days
Growing degree days are a concept of phenology that uses threshold temperatures to predict when plants and pests will reach maturity. It is based on the idea that plants and pests develop only above a certain threshold temperature. By tracking the high and low of each day, we can assign each day a specific number of units, and, knowing the maturity rate of specific plants and pests, translate that into an accurate prediction of when they should mature.  The method is more accurate than simply relying on a calendar.

Hard edge
In gardening, a hard edge on a lawn gives it a defined border. It is usually accomplished by digging a shallow trench along the grass edge.

Hardscape
The hardscape areas of a property are the nonliving features of a landscape, such as paved areas, concrete and stones. It does not include living, “softscape” features such as lawn grasses and garden plants.

Hyrdoseeding, hydromulching
Hydroseeding and hydromulching involve spraying water-based mixtures to help establish grass or prevent erosion. Hydromulching uses water, mulch and a substance to help it stick. Hydroseeding adds seed and fertilizer to the mix. Hydroseeding can be used on yards, but is more often used on slopes. The method is generally less expensive than sod but more expensive than seeding.

Inflorescence
In grasses, an inflorescence is the complete flowering part of the plant, including the stem, stalk and all its flowers. The arrangement of an inflorescence can often be complex, with multiple flowers coming off a single stalk.

Kentucky Bluegrass
Kentucky Bluegrass is a dense, cool-season grass introduced to the United States by early European settlers. Because of its low shade tolerance, Bluegrass seed is often sold in a blend with other grass seeds that do better in the shade. A vigorous spreading grass, it grows most actively in the spring and fall.

Lawn aerator
A lawn aerator is a garden tool that pokes air holes into the turf. There are two basic types: Spike aerators and core aerators. Spike aerators push into the soil to create the holes. Core aerators push a cylinder into the soil, extract a plug and deposit it on top of the grass. Core aeration is the preferred method to relieve compacted soils.

Lawn spreader
A lawn spreader is a tool for distributing material, such as grass seed or fertilizer, across the lawn. Broadcast or rotary spreaders scatter the material in a fan shape. Drop spreaders are more precise and drop the material straight to the ground. Spreaders can be hand-held or push models. For larger applications, electric or gas motor spreaders are available.

Leaf blower
Leaf blowers mechanically move leaves and other lawn trimmings by the force of air. Blowers can be gas-powered or electric, hand-held or shoulder-mounted.

Liming
Liming is the application of lime to raise the pH of overly acidic soil. Most lawn grasses do best in soil with slightly acidic, near-neutral soil pH. A soil test will reveal whether your lawn needs liming, and the test may also recommend the volume of lime needed. Lime can be applied any time, but applying just before winter sets in will allow the freezing and thawing to better incorporate the material into the soil.

Marcelling
Marcelling is an undesirable washboard or wavy pattern on top of turf caused by reel mowers, generally due to mowing at too high a speed. Sometimes called bobbing.

Mower
A mower is a machine used to cut lawn grass. Before mowers were invented, lawn grass was shortened by scythes or grazing animals. The lawn mower was invented by English inventor Edwin Beard Budding, who patented the first lawn mower in 1830. Over the years, they have evolved into many forms. Some are still like the Budding mower and are pushed manually. Reel, or cylinder, mowers have a rotating cylinder comprised of several blades that chop the grass with a scissor-like cut. Others are powered by electric motors or gas engines and usually accomplish the cut via a single, horizontally rotating blade. They can be push-from-behind mowers or riding mowers. The latter category includes both sit-down and stand-on varieties.

Mulch
In lawn care, mulch consists of grass clippings and leaf debris chopped by the mower and left to decompose on the lawn. By mulching clippings instead of bagging them, the mulch returns much-needed nutrients to the grass, reducing the need to fertilize.

Mulching blade
Also known as a “3 in 1” or an “all-purpose” blade, the mulching lawn mower blade is intended for use on lawns where the grass will be returned to the ground to decompose. They often have a curved shape and an extra cutting edge and are designed to lift the cut grass up toward the deck of the mower so that the clipping is cut several times before it falls to the ground.

Native grasses
Native grasses are those grasses indigenous to a specific region. Native North American grasses include the prairie grasses that once covered major parts of what would become the United States. Most common U.S. lawn grasses are not native species. One exception is Buffalograss, now a popular choice for natural lawns. Many popular ornamental garden grasses are native species, including switchgrass, big and little bluestem, and Indiangrass. See “Native Grasses — Are They Right for Your Lawn?

Nutrient deficiency
A deficiency happens when grass doesn’t get enough of a nutrient it needs. This can occur because the nutrient isn’t present or because improper soil pH ties up nutrients and makes them unavailable to the plant. Nutrient-deficient grass may turn pale, yellow and brown.

Organic matter
Organic matter is nutrient-rich material created as plant and animal matter decomposes. It is an important component to healthy soil. You can reduce your reliance on chemical fertilizers by incorporating organic matter, such as lawn clippings themselves: Let them fall to the ground and decompose instead of bagging them and sending them to a landfill. Compost created from kitchen and garden material is another source of organic nutrients. See “Guide to Organic Lawn Care.”

Overseeding
Overseeding is the practice of adding seed to an existing lawn. It is commonly done to fill in bare spots, to introduce new grass varieties with different strengths or tolerances, and to build grass density or alter a lawn’s color. To overseed a lawn, mow it lower than usual, collect the clippings and rake. This prepares the soil so seed can make contact needed for rooting. Overseed cool-season grasses in spring or fall. For warm-season grass types, overseed in late spring through mid-summer. See “Overseeding: A Quick Guide.”

Patch diseases
Patch diseases are a group of fungal diseases that attack lawns, particularly those that suffer from excessive thatch, poor soil or too much or too little nitrogen. Patch diseases typically show up as rings or semicircles of dead grass. Brown patch comes from the Rhizoctonia solani fungus. It can attack a wide variety of grasses, usually in wet and hot mid-summer conditions. Summer patch comes from the Magnaporthe poae fungus. Patch diseases are best prevented by correcting poor cultural practices. Treatment may include overseeding, fungicide, and amending the soil to correct imbalances.

pH
The term pH refers to a common scale that measures the acidity or alkalinity of a solution. The commonly used pH scale runs from 0 to 14, with acidity at the low end, alkalinity at the high end, with 7 considered neutral. Technically, it is a measure of hydrogen ion in a solution (the letters pH stand for “potential of hydrogen”). Soil pH influences the ability of your grass to access essential nutrients, including those added through fertilizers. Most grasses do best in slightly acidic, near-neutral soil pH. See “ABCs of pH: Why, How and When to Soil-Test Your Lawn.”

Phenology
Phenology is a branch of science that looks at the relationships between seasonal events. In common practice, that means keeping track of such things as the first bloom of certain plants or the first arrival of migratory birds and using those as the trigger for planting seeds, rather than relying on the calendar.

Plugs
Plugs are individual grass plants, grown in trays, or small 2- to 4-inch sections of turf containing roots, soil and grass. They are a less expensive way of establishing a lawn or patching a bare spot than full slabs of sod, but more expensive than seed. The recommended spacing between plugs varies based on the grass variety. Fast, spreading grasses warrant wider spacing; slow-growing types are spaced more closely.

Pole edger
A pole edger, aka stick edger, is a common variety of edger with the cutting head at the end of a pole. Pole edgers offer more maneuverability than heavy walk-behind edgers. They’re available in lightweight corded electric models, cordless battery-operated models and gas-powered versions.

Pre-emergent herbicide
A pre-emergent herbicide prevents germinating weed seeds from emerging and taking root. Some pre-emergent products also contain active ingredients that kill weeds after they sprout. Timing is critical: Warm-season (summer) weeds begin to germinate when the soil temperature reaches 55 degrees F. Cool-season (winter) weeds germinate in the fall. The exact timing and the type of herbicide you should apply will depend on your climate and the weed type. Pre-emergent herbicides can harm new grass seedlings and prevent grass seed from germinating, so avoid their use in recently planted areas or areas where you plan to seed. See “Using Pre-Emergent Herbicides to Kill Your Lawn’s Weeds.”

Pregerminated grass seed
Pregerminated seeding is an advanced grass seeding technique in which grass seeds are moistened to trigger germination before they are planted. Great care must be taken, as the temperature, level of moisture and timing of planting are all crucial to success. When done correctly, pregermination shortens the time needed to establish new seed.

Radicle
The radicle is the first baby root that emerges from a seed and becomes the plant’s primary root. When reseeding lawns, you want good contact between the seed and the soil. Otherwise, the radicle will die out before taking root.

Red thread
Red thread is a common summer lawn fungus disease. More cosmetic than deadly, it gives a lawn a ragged look through the reddish blades that give it its name. Red thread is commonly caused by improper watering and fertilization practices. Compacted soil and excess thatch are also to blame.

Reel mower
Reel, or cylinder mowers, have a rotating cylinder comprised of several blades that chop the grass with a scissor-like cut. The first mower, invented in 1831, was a reel mower.

Rhizome
Rhizomes are horizontal underground stems by which some types of grasses spread to develop new roots and shoots. Because the spreading stems are protected underground, rhizomatous grasses hold up very well to heavy foot traffic and recuperate quickly from injuries.

Ryegrass
Ryegrass is a genus of cool-season grasses unrelated to cereal rye used in breads and flours. Known for fast germination, ryegrasses are often used in seed mixes for quick establishment, early color and erosion control. Annual ryegrass naturally dies after one season, regardless of climate. Perennial ryegrass comes back year after year when grown in the appropriate zone. Southern lawn owners often overseed their soon-to-be-dormant, warm-season lawns with ryegrass in fall for temporary winter color.

Scarifier
A scarifier, or dethatcher, is a tool that is used to remove thatch from lawns. Scarifiers come in many forms, from manual models to tow-line scarifiers that can be pulled behind a tractor. Proper timing is crucial or a scarifier can harm your lawn instead of help.

Seed, seeding
Seeding – that is, establishing a lawn from seed – is a common and relatively inexpensive way to grow grass. Seed can be used to establish a new lawn, renovate an existing one or fill in bare spots. See our how-to article, “Growing Your Lawn From Grass Seed.”

Senescence
In plants, senescence is the gradual deterioration associated with aging and eventually death. Some forms of senescence are stress-induced seasonal events, such as leaf senescence, which results in brilliant fall colors in some trees. Some senescence-like processes are imposed on plants, as when weed-killers inhibit a plant’s ability to divide and grow.

Skid-steer mower
A skid steer is a heavy-duty, boxy, outdoor machine with lift arms that support a variety of labor-saving attachments. A skid-steer mower attachment allows a skid steer to be used for heavy-duty lawn and brush cutting.

Slit seeder, slice seeder
A slit seeder, sometimes called a slice seeder, is an advanced seeding tool. There are many types, but what they all have in common are blades that slice into the soil, plus a hopper that dispenses seeds into the open slits.

Sod
Sod is your grass, plus the interwoven mass of soil and other organic matter held together by the grass roots. Sod farms generally sell sod by the pallet, square foot, square yard or roll. A typical pallet covers 450 square feet, using rolls that measure 2 feet by 5 feet. See “How to lay down grass sod for a yard.”

Softscape
In landscaping terms, the softscape portions of a property are those that are soft and living, including lawns and garden plants. This differentiates them from the hardscape, which is such nonliving items as stone and cement.

Soil structure
Soil structure refers to the physical arrangement of the solid soil particles (sand, clay and silt) and the pore spaces between them. The ideal soil structure for growing grass provides sufficient porosity to allow for healthy root growth and air, water and nutrient movement. Heavy foot traffic that compacts soil damages its structure. Incorporating organic matter and aerating can improve soil structure.

Soil test
Soil tests should be done before planting new lawns and gardens, and periodically once they are established. Test more often in problem areas. A basic soil test will reveal your soil pH and nutrient levels such as phosphorus, potassium, calcium and magnesium. Most soil testing laboratories do not test for nitrogen because it moves through soil quickly. But test recommendations will include how much annual nitrogen to apply to your lawn and, if needed, how much lime to apply to raise pH to levels needed for healthy grass growth. Your local county extension agent can provide information and, in many cases, testing kits.

Spikelet
A grass spikelet is the flowering portion of a grass plant. Spikelets of most grass species contain male and female structures. Grass flowers are wind-pollinated.

Sprigs, sprigging
Sprigs are 3- to 6-inch sections of the horizontal stems (below-ground rhizomes or above-ground stolons) of creeping grasses. Sprigging is the act of planting the sprigs to start a lawn or to patch bare spots. In sprigging, cut the creeping stems into sections so that two or three nodes are present on each, and then plant them in shallow furrows so the nodes and roots are covered with soil, but the foliage remains uncovered.

Standard mowing blade
Also known as “2 in 1” or “high rise” blade, the standard lawn mower blade is intended to allow the operator to decide whether to collect the grass clippings in a bagging system or let them fall to the ground. A standard blade does not mulch clippings.

St. Augustinegrass
This salt-tolerant warm-season grass tolerates some shade and grows in the subtropical zone of the United States — the states that border the Gulf of Mexico. It has broad, coarse leaves and spreads aggressively with long stolons (above-ground runners). St. Augustine grass is one of the few species of grass almost exclusively established from sod, plugs or sprigs. While it will send out seed stalks if left unmown, the seeds are rarely viable.

String trimmer
String trimmer is one of many of the generic names for a device used to trim and edge lawns via a flexible, fast-spinning string. Other names include “weed-whip,” “strimmer,” “weed whacker” and “weed wacker.”

Stolon
Stolons, sometimes called runners, are specialized, horizontal stems by which some grass varieties spread along the soil surface. Nodes on the creeping runners can form new crowns, roots and shoots to create new grass plants.

Sward
A once-popular word that has fallen into disuse meaning a patch of land covered by grass. To form a sward is to become covered by grass. The word is from the Old English word sweard, which originally meant “skin.”

Syringing
Syringing is lightly watering a lawn so that the blades of grass are moistened without the water getting down to the soil. The technique is used to cool down a lawn in high heat to reduce stress on established grass. Syringing is not sufficient to keep newly seeded lawns adequately moist.

Thatch
The average blade of grass lives 40 days and then drops to the soil and begins to decompose. Over time, a layer of decomposing matter develops between the ground and the green. That intermingled mass is called thatch. A little thatch is beneficial as it moderates the soil from temperature extremes. But if it builds up faster than it breaks down, it can rob the grass of moisture and air. If the thatch layer becomes excessive, properly timed dethatching is needed. See “Dethatching Your Lawn – a Comprehensive Guide.”

Topdressing
Topdressing is the process of adding a thin layer of sand or prepared soil mix to your lawn’s surface. It’s done for a variety for reasons: as a follow-up to core aeration, to add organic matter, to smooth your lawn’s surface or to speed thatch decomposition. See “Guide to Topdressing a Lawn.”

Tow-behind dethatcher
A tow-behind dethatcher is a simple wheeled device with multiple prongs extending from it that can be towed behind a tractor or riding lawn mower. The prongs drag along the ground to loosen built-up thatch and make a lawn healthier.

Transition zone
In terms of growing grass, this section of the central and eastern United States poses the greatest challenge. The transition zone includes the parts of the country with both hot summers that kill common cool-season lawn grasses and cold winters that kill common warm-season lawn grasses. The transition zone extends roughly from lower Pennsylvania and New Jersey southward through northern Georgia and westward along the nation’s midsection through Kansas, Oklahoma and northern Texas. See “Guide to Growing Grass in the Transition Zone.”

Vernation
Vernation refers to the way young leaves are arranged in grass shoots. The blade can be folded or rolled. You can tell the vernation of a grass plant by cutting across the sheath and looking inside. Folded vernation will look v-shaped, while rolled vernation will look circular. Knowing the vernation comes in handy when identifying which type of grass you have.

Warm-season grass
Warm-season grasses get their name because they experience their peak growth period during warm summer months. Most of the common warm-season lawn grasses in the United States are tropical natives that can’t survive northern winters. However, many cold-hardy native North American prairie grasses are warm-season grasses, too. Warm-season lawn grasses, such as St. Augustine, Bermudagrass and Zoysia, typically go dormant and turn brown during winter months.

Weed Eater
The Weed Eater is the brand name of the first string trimmer. It was invented by Houston dance studio owner George Ballas and introduced in 1971. Ballas had been trying to clear brush on his 2-acre homestead. While at a car wash, the swirling brushes gave him an idea. He punched holes in a can, put a wire through it and added a motor to spin the unit. Voila! The Weed Eater was born. The invention revolutionized professional lawn care.

Winterkill
Winterkill, or winter kill, refers to grass that has been done in by wintry extremes. Grown in the proper climate zones, most lawn grasses snap back after winter, but severe or extended cold weather and lack of insulating snow cover can partly or completely kill off a lawn. Common causes of winterkill include cold desiccation, in which uncovered grasses continue to lose moisture in the cold, and snow mold, which is the collective name for a variety of fungal diseases that cause crusty or fuzzy patches on a lawn. See “How To Repair Winter’s Damage to Your Lawn.”

Zero-turn mower
As its name implies, a zero-turn mower has a turning radius of effectively zero. It can pivot in a circle, making mowing more efficient. That ability makes it a favorite among professional lawn care providers, but do-it-yourselfers with large lawns have begun to purchase them as well, despite their high price tags.

Zoysiagrass
Zoysia is a genus of drought-tolerant, warm-season grasses native to Asia. The three main species of Zoysiagrass used for turf are Zoysia matrella (aka Manila grass), Zoysia tenuifolia, and Zoysia japonica. Zoysia japonica is more cold-tolerant than other common warm-season lawn grasses, making it a popular choice in the transition zone. The genus is named after Karl von Zois, an 18th-century Slovenian botanist.

Last update: Feb. 25, 2020