No Thanks
Let
Keep In Touch With MarthaStewart.com

Sign up and we'll send inspiration straight to you.

Martha Stewart takes your privacy seriously. To learn more, please read our Privacy Policy.

Going Green: Gardening by Zone

Martha Stewart Living, September 2007

Gardeners have an old adage: right plant, right place. No gardener worth her pruning shears would plant a rose in dry shade, yet millions of us do the equivalent with our lawns, growing grasses that aren't suited to the climate we live in, much less the conditions of the front yard. The result is a heavy reliance on synthetic fertilizers and pesticides, necessary to chemically coddle the grasses and cajole them into growing.

But by choosing grass for your lawn as carefully as you would plants for your garden, it's possible to grow organic, sustainable turf that thrives because its needs are met naturally. Properly sited plants -- turfgrass included -- need less fertilizer and are better equipped to withstand an attack by insects or disease. If they do get attacked, they recover from the damage quickly, so they seldom look worse as a result.

For all the jokes about lawns being nothing more than a suburban affectation, the green carpets deserve a lot of credit. Turf is a superior ground cover because it prevents erosion. A healthy lawn absorbs rainfall four to six times more effectively than a farm field does, and the dense roots and top growth of turf prevent pesticides from moving through soil and contaminating groundwater. Like a rug, turf muffles sound. It also cools the environment; its surface is often 25 degrees cooler than a sidewalk's on a hot day. In addition, turf reduces glare and captures air pollution and dust.

Taking a lawn to the next level by going organic can happen all at once (covering the area with seed or sod) or gradually (filling in patches with seeds, sprigs, or plugs). Either way, pick grass suited to the geography. The major factors that determine how well turf will do are light, temperature, precipitation, and soil. Turf is divided into cool- and warm-season grasses, but to address the other factors that affect its growth, it's helpful to split the continental United States into four zones. An environmentally friendly lawn isn't labor-free. It still requires regular care. But while you're tending to it, it will be a safe, healthy place to work.


Cool Humid Zone

This zone is characterized by mild to hot summers and cold winters. Precipitation ranges from 25 to 45 inches a year. Soils are often acidic to the east of the Rockies, while west of the Rockies, soils are neutral to slightly alkaline.

Fine Fescue
Appearance: Medium green; fine texture.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in acidic soil. Best choice for dry shade. Good drought tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Clump-forming.
Wear: Poor wear resistance. Fair to poor recuperation.
Good to know: May turn bronze in full sun. Tight growth inhibits weeds. Usually mixed with other grasses for a more uniform appearance.

Kentucky Bluegrass
Appearance: Dark green; fine texture. Medium to high density.
Establishment: Introduce to lawn by seed or sod.
Growing conditions: Likes well-drained, fertile soils. Good drought tolerance. Poor shade tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Reproduces via rhizomes.
Wear: Good wear tolerance and recuperation. Often used on athletic fields because of its ability to recover.
Good to know: Vigorous rhizomes make it a good choice for compacted soil.

Perennial Ryegrass
Appearance: Medium green; fine texture.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in moist, moderately fertile soils. Best on well-drained sites. Tolerant of compacted soil. Poor drought tolerance. Poor temperature tolerance. No shade tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Clump-forming.
Wear: Good wear tolerance but poor recuperation.

Tall Fescue
Appearance: Medium green; medium texture.
Establishment: Introduce to lawn by seed or sod.
Growing conditions: Tolerates a wide range of soil conditions, including infertile sand, compacted clay, and alkaline and saline soils. Good drought tolerance. Best heat tolerance of the cool-season grasses. Poor cold tolerance. Fair to good shade adaptability.
Mowing: Best height is 3 to 4 inches. Will not tolerate low mowing.
Growth spread: Clump-forming.
Wear: Superior wear resistance but slow recuperation.
Good to know: Not a good mix with other grasses; the lawn won't look uniform. Best sown in mid-August because it establishes itself better in warmer temperatures.


Cool Arid and Semiarid Zone

Humidity and precipitation in this zone are usually low, often leading to summer drought. Mean temperatures in the summer are 70 to 80 degrees, and winters are characterized by temperatures from 20 to 35 degrees. Soils in this zone tend to be alkaline and may be very saline.

Buffalo Grass
Appearance: Grayish green; fine texture.
Establishment: Introduce to lawn by seed, plugs, or sod.
Growing conditions: Most drought-tolerant turf in the United States, requiring almost no irrigation. Does well in heavier, fine-textured soils. Poor shade tolerance.
Mowing: Best height is 2 inches. Grows slowly.
Growth spread: Reproduces via stolons.
Wear: Good wear tolerance.
Good to know: Pest resistant. Good for erosion control.

Crested Wheatgrass
Appearance: Medium green; medium texture.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in well-drained, loamy soils. Fair shade adaptability. Excellent drought resistance. Good cold tolerance. Fair heat tolerance.
Mowing: Best height is 1 1/2 to 2 1/2 inches.
Growth spread: Clump-forming.
Wear: Medium wear tolerance but poor recuperation.

Kentucky Bluegrass
Appearance: Dark green; fine texture. Medium to high density.
Establishment: Introduce to lawn by seed or sod.
Growing conditions: Likes well-drained, fertile soils. Good drought tolerance. Poor shade tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Reproduces via rhizomes.
Wear: Good wear tolerance and recuperation. Often used on athletic fields because of its ability to recover.
Good to know: Vigorous rhizomes make it a good choice for compacted soil.

Perennial Ryegrass
Appearance: Medium green; fine texture.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in moist, moderately fertile soils. Best on well-drained sites. Tolerant of compacted soil. Poor drought tolerance. Poor temperature tolerance. No shade tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Clump-forming.
Wear: Good wear tolerance but poor recuperation.

Roughstalk Bluegrass
Appearance: Light yellow-green; fine texture. High density.
Establishment: Grows best when planted by seed.
Growing conditions: Great for wet, poorly drained soils in shade. Very poor drought tolerance. Excellent cold tolerance. Poor heat tolerance.
Mowing: Best height is 3 to 4 inches.
Growth spread: Reproduces via stolons.
Wear: Poor wear resistance. Fair recovery.

 

Warm Humid Zone

Tropical ocean currents influence this zone, which is distinguished by high humidity, hot summers, warm winters, high rainfall (50 to 65 inches a year), and acidic soils.

Bahia Grass
Appearance: Light green; coarse texture. Produces open, low-density turf.
Establishment: Introduce to lawn by seed, sprigs, or plugs.
Growing conditions: Tolerates poor soils, including dry, infertile, sandy soils. Very good drought tolerance. Fair shade tolerance. Poor salt tolerance. A good low-maintenance grass for roadsides.
Mowing: Best height is 1 1/2 to 3 inches. Because the grass is very tough, a rotary mower is a must.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Wears well. Poor to fair recuperation.
Good to know: Resists pests.

Bermuda Grass
Appearance: Deep green; fine texture; low-growing; good density.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in poor soils, such as compacted clay.
Mowing: Best height is 1/2 to 1 1/2 inches. Needs frequent mowing.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Good recuperative ability.
Good to know: Least shade tolerant of subtropical grasses. Dormant (brown) when temperature falls below 60 degrees.

Carpet Grass
Appearance: Medium green; coarse texture.
Establishment: Introduce to lawn by seed.
Growing conditions: Tolerates partial shade. Poor drought and salt tolerance. Good for warmest regions of the South, especially on acidic, infertile, moist soils.
Mowing: Best height is 1 to 2 inches. Because the grass is very tough, a rotary mower is a must.
Growth spread: Reproduces via stolons.
Wear: Not suited to high-traffic areas.
Good to know: Few disease and insect problems. Good for erosion control.

Centipede Grass
Appearance: Light green; coarse texture.
Establishment: Introduce to lawn by sprigs, plugs, or sod.
Growing conditions: Good choice for acidic, infertile soils in warmest regions. Fair drought tolerance. Fair shade tolerance. Poor salt tolerance.
Mowing: Best height is 1 to 2 inches. Doesn't need frequent mowing.
Growth spread: Reproduces via stolons.
Wear: Least wear resistant of warm-season grasses, with poor recuperation.
Good to know: Tends to stay green during periods of drought.

Saint Augustine
Appearance: Medium green; coarse texture.
Establishment: Introduce to lawn by plugs or sod.
Growing conditions: Least cold tolerant of warm-season grasses. Prefers moist, well-drained, sandy soils. Good salt tolerance. Excellent shade tolerance.
Mowing: Best height is 1 1/2 to 3 inches.
Growth spread: Reproduces via stolons.
Wear: Poor wear tolerance, but will recuperate quickly.

Seashore Paspalum
Appearance: Dark green; fine texture.
Establishment: Introduce to lawn by seed, sprigs, or sod.
Growing conditions: Good drought and salt tolerance. Poor shade tolerance.
Mowing: For very dense turf, the best height is 1 to 2 inches.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Excellent recuperation.
Good to know: Keeps good color even in cold weather. The grass's dense growth and aggressive spreading make it hard for weeds to establish themselves.

Zoysia
Appearance: Medium green (turns the color of straw in cool weather); medium texture.
Establishment: Introduce to lawn by sprigs or plugs (establishment can be slow up to two years), or by seed or sod.
Growing conditions: Grows best in well-drained soils. Good drought, shade, and salt tolerance.
Mowing: Best height is 1/2 to 1 inch. A sharp reel mower works best.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Poor recuperation.

 

Warm Arid and Semiarid Zone

This zone is characterized by hot summers, warm winters, low precipitation (5 to 20 inches a year), and very low humidity. Midsummer temperatures usually range from 80 to 95 degrees, and winter temperatures are 35 to 53 degrees. Soils tend to be alkaline and may be very saline.

Bermuda Grass
Appearance: Deep green; fine texture; low-growing; good density.
Establishment: Introduce to lawn by seed.
Growing conditions: Grows well in poor soils, such as compacted clay.
Mowing: Best height is 1/2 to 1 1/2 inches. Needs frequent mowing.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Good recuperative ability.
Good to know: Least shade tolerant of subtropical grasses. Dormant (brown) when temperature falls below 60 degrees.

Seashore Paspalum
Appearance: Dark green; fine texture.
Establishment: Introduce to lawn by seed, sprigs, or sod.
Growing conditions: Good drought and salt tolerance. Poor shade tolerance.
Mowing: For very dense turf, the best height is 1 to 2 inches.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Excellent recuperation.
Good to know: Keeps good color even in cold weather. The grass's dense growth and aggressive spreading make it hard for weeds to establish themselves.

Zoysia
Appearance: Medium green (turns the color of straw in cool weather); medium texture.
Establishment: Introduce to lawn by sprigs or plugs (establishment can be slowup to two years), or by seed or sod.
Growing conditions: Grows best in well-drained soils. Good drought, shade, and salt tolerance.
Mowing: Best height is 1/2 to 1 inch. A sharp reel mower works best.
Growth spread: Reproduces via rhizomes and stolons.
Wear: Poor recuperation.

 

Transition Zone

In some areas, it may be too hot in summer for cool-season grasses and too cold in winter for warm-season ones. These locales, taken together, form the transition zone, which overlaps other zones. Overseeding (see "Talking Turf," below) can help maintain a healthy lawn throughout the year.

In Kentucky, Missouri, Virginia, and West Virginia, cool-season grasses such as Kentucky bluegrass, perennial ryegrass, and tall fescue do well.

In warmer areas of the transition zone, such as Tennessee, North Carolina, northern Georgia, northern Alabama, and the Texas panhandle, tall fescue is a good choice.

At the southern reaches of these warmer states, you can also try warm-humid-zone grasses, such as Bermuda grass or zoysia.

An intermediate ryegrass (Lolium hybridum), which is a cross between perennial and annual rye, can be used to overseed any warm-season turf that goes dormant in winter. The premise: The rye will die off when the warm-season grasses come out of dormancy.

Talking Turf: Vocabulary
Aerating
The process of cutting small holes in the turf for easier penetration of air, water, and nutrients. This is best done when the grass is actively growing.
Clump-Forming
Growing in distinct bunches or mounds.
Hydroseed
The process of spraying a slurry of grass seed, water, fertilizer, and mulch over an area for quick establishment of a lawn. The mixture is often used on steep slopes for erosion control.
Overseed
The act of spreading seed on top of an existing lawn to fill in bare areas, introduce new grass types, or (particularly in the South) plant cool-season grasses to maintain a lawn's color through winter.
pH
A measure of a soil's alkalinity or acidity. The pH scale ranges from 0 to 14, with a soil's pH rising with increasing alkalinity (7 to 14) and decreasing with increasing acidity (0 to 7).
Plug
A small piece of sod. Plugs can be used to establish a new lawn or fix the bare spots in an existing lawn. They tend to establish more easily than sprigs but take a longer time to fill in a lawn.
Reel Mower
A mower with multiple blades mounted on a cylinder. The blades cut against a bar, making precise cuts. Reel mowers are ideal for lower mowing heights (important for grasses such as Bermuda grass and zoysia). The mowers are available in manual or gas-powered models.
Rhizome
Horizontally growing stem that spreads underground.
Rotary Mower
A mower with a blade that spins in a horizontal plane from a central rod. Its advantages include the ability to cut tall grass and make tight turns. Tough grasses, such as Bahia grass and carpet grass, are best cut using a rotary mower with a sharp blade. The mowers are available in gas- and electric-powered models.
Sod
A dense mat of grass cut into large strips. Sod, which eventually grows into the soil upon which it's laid, can be rolled out to create a new lawn instantly.
Sprig
A grass cutting with roots. Sprigs can be used to establish a new lawn or fix the bare spots of an existing lawn.
Stolon
Horizontally growing stem that spreads aboveground.

Cool-Season Grass Tips
Fertilizing
Don't fertilize blue-grasses, tall fescue, and ryegrasses in early spring (you'll end up with excess shoot growth at the expense of root growth). Instead, add nutrients from mid-May to Memorial Day. You can fertilize again around Labor Day. Fine fescue requires only one fertilization per year. Apply it around Labor Day. For any of these jobs, we recommend organic fertilizer.
Aerating
Spring and fall -- when active root growth occurs -- are the best times of year to aerate cool-season grasses.
Watering
Cool-season turfgrasses need 1 to 1 1/2 inches of water per week. It's best to set a sprinkler to water the grass between midnight and 4 a.m., which corresponds with the natural dew period. This will reduce the amount of water loss to sun and wind. Water less if rainfall is frequent.
Seed
The best time of year to seed is from the last week of August to the last week of September. During this period, the grass won't have competition from annual summer weeds, such as crabgrass.
Sod
Lay down sod in spring or fall, when the temperatures are moderate and growth is most active.

Warm-Season Grass Tips
Fertilizing
Apply organic fertilizer to warm-season grasses in late spring and a second time during the summer.
Aerating
For warm-season grasses, aerating should be done when the grass is completely green and actively growing, usually from midspring to midsummer.
Watering
Many warm-season grasses are drought tolerant, but others are not. Watering recommendations vary depending on the type of grass.
Growing
Even in the South, warm-season grasses become dormant during winter months. To maintain the lawn's color, overseed cool-season species with your warm-season species when cool weather sets in. The turf will stay green all winter. Later, as the temperature begins to rise, the cool-season grasses will die off and the warm-season grasses will take their place.