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Chapter 21 Selecting the proper grass.

Objectives:

Upon completion of this chapter, you should be able to

* list six factors used in the comparison of different turfgrasses

* list the information required by law on grass seed labels

* explain the differences between single-species plantings, single-species blends, and mixtures of species

Turfgrasses are among the oldest plants used for landscaping. They are the most common choice for surfacing the outdoor room. A neatly trimmed lawn of good quality is not only comfortable to walk on, but ideal for many athletic and recreational activities. Because the growing point of the turfgrass is at the crown of the plant, near the soil, it is protected. This permits turfgrasses to be mown and walked upon repeatedly.

Comparison of Turfgrasses

Most turfgrasses used in landscapes are perennial, surviving from one year to the next. Nearly all species reproduce from seed, although several can be reproduced vegetatively, without pollination and seed production. A typical grass plant produces new leaves throughout the growing season. During the growing season, the turfgrasses will increase beyond the number of seeds sown. One of the objectives of good lawn development is to encourage turf growth as quickly and as evenly aspossible.

Growth Habits

* Grasses have differing growth habits, which result from the three different ways that new shoots are produced, Figure 21-1. Rhizome-producing (rhizomatous): A rhizome is a horizontal underground stem. New shoots are sent to the surface some distance out from the parent plant. Each new plant develops its own root system and is independent of the parent plant.

* Stolon-producing (stoloniferous): The shoots extending out from the parent plant are above ground. They are called stolons. New plants develop independently as described above. Some grasses are both rhizomatous and stoloniferous.

* Bunch-type: New shoots are produced from the sides of the plant, gradually increasing the plant's width.

[FIGURE 21-1 OMITTED]

Rhizome and stolon-producing grasses tend to reproduce more quickly and evenly than bunch-type grasses. Therefore, the bunch-type require more seed and closer spacing in order to cover an area quickly and without clumps.

Texture, Color, and Density

Grass texture is mostly a way of describing the width of the grass leaf (blade). The wider the blade is, the coarser will be the texture. Generally, fine-textured grasses are more attractive than coarse-textured grasses. They are also more expensive. The color of a grass and its density will also differ among species. Colors can vary from pastel greens to dark, bluish tones. Density refers to the number of leaf shoots that a single plant will produce. It can range from sparse to thick, depending upon the type of grass.

Size of Seed

The size of the seed is another reason for variation in the quality and quantity of grass seed mixes. Fine-textured grasses have very small seeds. Coarse-textured grass seeds usually are much larger. Thus, a pound of fine-textured grass seed contains considerably more seeds than a pound of coarse-textured grass seed.

Because of the greater number of seeds per pound, a pound of fine-textured grass seed plants a larger area of land. For example, a pound of fine-textured Kentucky bluegrass contains approximately 2,000,000 seeds. That number of seeds plants about 500 square feet of lawn. A pound of coarse-textured tall fescue contains 227,000 seeds; therefore, only 166 square feet can be planted with a pound of this particular seed.

Other comparisons can further point out the difference in seed sizes. For example, there are as many seeds in 1 pound of bluegrass as there are in 9 pounds of ryegrass; and as many seeds in a pound of bentgrass as there are in 30 pounds of ryegrass.

Soil and Climatic Tolerance

Most grasses, like almost all other plants, do best in good-quality, well-drained soil. However, every state contains landscape sites that fall short of the ideal conditions preferred for turfgrass success. Some grasses can adapt to a wide range of soil conditions, while others are very limited in their adaptability.

Similarly, some grasses tolerate high humidity and reduced sunlight; others do not. Some thrive in the subtropics and tropics; others are better-suited for temperate and subarctic regions.

Grasses are often grouped into two categories based upon the temperatures at which they grow best:

* Cool-season grasses are favored by daytime temperatures of 60 to 75 degrees F.

* Warm-season grasses are favored by daytime temperatures of 80 to 95 degrees F.

Figure 21-2 shows the peak growth rates of the two types of grasses. Knowledge of the optimum growing temperatures of grasses explains why northern lawns are often brown and dormant in midsummer when the days are very warm. Likewise, warm-season grasses do not really flourish in early spring and late fall when temperatures fall below the optimum temperature.
Common Warm-Season    Common Cool-Season
      Grasses               Grasses

Bermuda grass         Kentucky bluegrass
zoysia grass          red fescue
centipede grass       colonial bentgrass
carpet grass          ryegrass
St. Augustine grass
Bahia grass
buffalo grass


[FIGURE 21-2 OMITTED]

Figure 21-3 illustrates the climatic regions of the continental United States that are favorable for the growth of the grasses listed and others. Any seed purchased for planting in a certain climatic region should be composed of the appropriate grasses.

Use Tolerance

Under the same conditions of use, some grasses will survive and others will quickly wear away. Some will accept heavy use and recover quickly, while others will recover much more slowly. Some can accept the compaction of heavy foot traffic and still look good; yet others may discolor and slow their rates of growth.

Disease and Insect Resistance

Certain grasses possess greater resistance than others to insect and disease pests. The resistance may be natural or may have developed through the efforts of plant breeders. Many grasses are continually being improved by horticultural scientists searching for features such as better color, resistance to drought, shade tolerance, and pest resistance.

[FIGURE 21-3 OMITTED]

In "A Comparison Chart for Turfgrasses" in this chapter, many of the most commonly used turfgrasses are compared.

Purchasing Grass Seed

Grass seed is sold in small quantities through retail outlets such as garden centers, supermarkets, hardware stores, and department stores. It is also sold in bulk amounts through wholesale suppliers. Professional landscapers usually purchase seed wholesale. However, most clients have purchased packaged seed from retailers in the past. They may not understand why the seed selected by the landscaper is priced higher than expected. Landscapers must be prepared to explain why all grass seeds are not alike and how the quality of seed is measured.

The key to determining the quality of grass seed is the seed analysis label. The seed analysis label, which by law must appear on every package of seeds to be sold, gives a breakdown of the contents of the seed package on which it appears. The analysis label may be on the package itself, or, if the seed is being sold in large quantities, on a label tied to the handle of the storage container.

While legal definitions vary somewhat from state to state, most analysis labels contain the following information:

Purity. The percentage, by weight, of pure grass seed. The label must show the percentage by weight of each seed type in the mixture.

Percent Germination. The percentage of the pure seed that was capable of germination (sprouting) on the date tested. The date of testing is very important and must be shown. If much time has passed since the germination test, the seed is older and less likely to germinate satisfactorily.

Crop Seed. The percentage, by weight, of cash crop seeds in the mixture. These are undesirable species for lawns.

Weeds. The percentage, by weight, of weed seeds in the mixture. A seed qualifies as a weed seed if it has not been counted as a pure seed or a crop seed.

Noxious Weeds. Weeds that are extremely undesirable and difficult to eradicate. The number given is usually the number of seeds per pound or per ounce of weed seeds.

Inert Material. The percentage, by weight, of material in the package that will not grow. In low-priced seed mixes, it includes materials such as sand, chaff, or ground corncobs. Inert material is sometimes added to make the seed package look bigger. At other times, the inert material is already present in the seed and is not removed because the cost involved would raise the price of the seed.

Three sample analyses follow. Study the contents of each mixture and determine which would probably cost the most and which the least.

It is likely that Mixture C would be the most expensive. It contains the highest percentage of fine-textured grasses, no coarse grasses, and the lowest percentage of weeds. Mixture A would probably cost the least, since it contains a high percentage of coarse-textured grasses, the lowest percentage of fine grasses, and the greatest percentage of weeds. None of the mixtures is very poor in quality, since there are no crop or noxious weed seeds claimed by any.
Mixture A

Fine-Textured Grasses
  12.76 percent red fescue        85 percent germ.
   6.00 percent Kentucky
     bluegrass                    80 percent germ.

Coarse Grasses
  53.17 percent annual ryegrass   95 percent germ.
  25.62 percent perennial
    ryegrass                      90 percent germ.

Other Ingredients
  2.06 percent inert matter
  0.39 percent weeds--no
    noxious weeds

Mixture B

Fine-Textured Grasses
  38.03 percent red fescue        80 percent germ.
  34.82 percent Kentucky
    bluegrass                     80 percent germ.

Coarse Grasses
  19.09 percent annual ryegrass   85 percent germ.

Other Ingredients
  7.72 percent inert matter
  0.34 percent weeds--no
    noxious weeds

Mixture C

Fine-Textured Grasses
  44.30 percent creeping
    red fescue                    85 percent germ.
  36.00 percent Merion
    bluegrass                     80 percent germ.
  13.54 percent Kentucky
    bluegrass                     85 percent germ.

Coarse Grasses
  None claimed

Other Ingredients
  5.87 percent inert matter
  0.29 percent weeds--no
    noxious weeds


Mixtures, Blends, and Single-Species Lawns

Grass seed is commonly purchased either as a mixture or a blend. It is also available as a single species (such as all Kentucky bluegrass or all Chewings fescue). A mixture combines two or more different species of grass. A blend combines two or more cultivated varieties of a single species. Both mixtures and blends have their places depending upon the site and circumstances. Mixtures are most common in temperate zone landscapes; single-species plantings are more common in subtropical and tropical landscapes.

Mixtures sometimes have the disadvantage of variegated color and texture. This is a result of the different species they contain. They have the advantage of being able to tolerate mixed environmental conditions and can recover from insect and disease pests that would wipe out a single species.

Single-species turf plantings offer a more uniform appearance than mixtures. However, a single-species planting is often unable to adjust to severe changes in environmental conditions. It can also be completely destroyed by a single insect or disease invasion.

Blends attempt to retain the advantages of both mixtures and single-species plantings. If the cultivated varieties of the blend are carefully selected, a blend offers these advantages: uniform color and texture, resistance to damage from environmental changes, resistance to wear, resistance to pest injury, and the varieties in the blend will have similar maintenance needs.

Achievement Review

A. Not all turfgrasses are alike. They can be compared using different factors. Insert the correct factor into each of the following sentences.

1. Adapting to differences in pH, aeration, fertility levels, humidity, light, and temperatures measures a turf's -- .

2. Rhizomatous, stoloniferous, and bunchtype are different -- of grasses.

3. Blade width, color variation, and the number of shoots per plant are measures of -- .

4. The ability of turf to withstand the compaction of foot traffic indicates its level of -- .

5. Certain grasses will suffer pest damage more than other grasses because of their -- .

6. One pound of fine-textured grass differs from a pound of coarse-textured grass in many ways. One way is in the number and -- of the seeds.

B. What could cause a very high-quality grass seed purchased in the south to be unsuitable for planting in the north?

C. Of the three seed mixtures A, B, and C shown in this chapter, which mixture is most likely to result in a sparse second-year lawn? Why?

D. Why is a grass seed mixture usually preferable to a pure, single-species seed?

E. List and define the important terms found on a grass seed analysis label.

Suggested Activities

1. Grow some grasses. Start flats or flowerpots of pure grass species in the classroom. Compare fine-leaf and broad-leaf types. If possible, also grow samples of warm-season and cool-season grasses for comparison.

2. Obtain several grass seed mixtures from various sources and in as many price ranges as possible. Rank the mixtures on the basis of package appearance, advertised claims, and brand names. Rank the mixtures again, using the seed analysis labels as the measure. How closely do the package claims match the actual facts about the mixture as shown on the labels? How closely does the price ranking follow the quality ranking?

3. Make a seed count. Weigh 1/4-ounce quantities of a fine-textured grass and a coarse-textured grass. Be as accurate as possible. Count the number of seeds in each measure. Do the fine-textured seeds outnumber the coarse-textured seeds?

NOTE: Do not use redtop for the coarse-textured grass in this exercise. Its seeds are atypically small for a coarse grass.

Jack E. Ingels

State University of New York

College of Agriculture and Technology

Cobleskill, New York
A Comparison Chart for Turfgrasses

                     Cool Season
Grass                or            Growth              Leaf
Species              Warm Season   Habit               Texture

Bahiagrass           Warm          Rhizomatous         Coarse

Bermudagrass         Warm          Stoloniferous       Fine
                                   and rhizomatous

Bentgrass,           Cool          Bunch-type (with    Fine
Colonial                           short stolons and
                                   rhizomes)

Bentgrass,           Cool          Stoloniferous       Fine
  Creeping

Bentgrass, Redtop
  (see Redtop)

Bentgrass,           Cool          Stoloniferous       Fine
  Velvet

Bluegrass,           Cool          Bunch-type or       Fine
  Annual                           stoloniferous

Bluegrass,           Cool          Rhizomatous         Medium
  Canada

Bluegrass,           Cool          Rhizomatous         Fine
  Kentucky

Bluegrass,           Cool          Stoloniferous       Fine
  Rough

Bromegrass,          Cool          Rhizomatous         Coarse
  Smooth

Buffalograss         Warm          Stoloniferous       Fine

Carpetgrass,         Warm          Stoloniferous       Coarse
  Common

Carpetgrass,         Warm          Stoloniferous       Coarse
  Tropical

Centipedegrass       Warm          Stoloniferous       Medium

Fescue,              Cool          Bunch-type          Fine
Chewings

Fescue,              Cool          Rhizomatous         Fine
  Creeping Red

Fescue, Hard         Cool          Bunch-type          Medium

Fescue, Meadow       Cool          Bunch-type          Coarse

Fescue, Sheep        Cool          Bunch-type          Fine

Fescue, Tall         Cool          Bunch-type          Medium
                                                       to Coarse

Gramagrass,          Warm          Rhizomatous         Fine
  Blue

Redtop (a            Cool          Rhizomatous         Coarse
bentgrass)

Ryegrass,            Cool          Bunch-type          Medium
  Annual

Ryegrass,            Cool          Bunch-type          Fine
  Perennial

St. Augustinegrass   Warm          Stoloniferous       Coarse

Timothy,             Cool          Bunch-type          Coarse
  Common

Wheatgrass,          Cool          Bunch-type          Coarse
Crested

Zoysiagrass          Warm          Stoloniferous       Medium
(Japanese                          and rhizomatous
lawngrass)

Zoysiagrass          Warm          Stoloniferous       Fine
(Manilagrass)                      and rhizomatous

Zoysiagrass          Warm          Stoloniferous       Fine
(Mascarenegrass)                   and rhizomatous

                      Mowing         Fertilization. Pounds
Grass                 Height/        of Nitrogen Per 1,000
Species               Inches         Square Feet Per Year

Bahiagrass            1 1/2 to 2     1 to 4

Bermudagrass          1 to 2         4 to 9

Bentgrass,            1/2 to 1       2 to 4
Colonial

Bentgrass,            1/2 or less    4 to 8
  Creeping

Bentgrass, Redtop
  (see Redtop)

Bentgrass,            1/2 or less    2 to 4
  Velvet

Bluegrass,            1              2 to 6
  Annual

Bluegrass,           Does not       1 or less
  Canada             mow well

Bluegrass,           1 to 2 1/2     2 to 6
  Kentucky

Bluegrass,           1 or less      2 to 4
  Rough

Bromegrass,          Does not       1 or less
  Smooth             mow well

Buffalograss         1/2 to 1 1/2   1/2 to 2

Carpetgrass,         1 to 2         1 to 2
  Common

Carpetgrass,         1 to 2         1 to 2
  Tropical

Centipedegrass       1 to 2         1 to 2

Fescue,              1 1/2 to 2     2
Chewings

Fescue,              1 1/2 to 2     2
  Creeping Red

Fescue, Hard         Does not       1 or less
                     mow well

Fescue, Meadow       1 1/2 to 3     1 or less

Fescue, Sheep        Does not       1 or less
                     mow well

Fescue, Tall         1 1/2 to 3     1 to 3

Gramagrass,          Does not       1 or less
  Blue               mow well

Redtop (a            1 1/2 to 3     1 to 2
bentgrass)

Ryegrass,            1 1/2 to 2     2 to 4
  Annual

Ryegrass,            1 1/2 to 2     2 to 6
  Perennial

St. Augustinegrass   1 to 2 1/2     2 to 6

Timothy,             1 to 2         3 to 6
  Common

Wheatgrass,          1 1/2 to 3     1 to 3
Crested

Zoysiagrass          1/2 to 1       2 to 3
(Japanese
lawngrass)

Zoysiagrass          1              2 to 3
(Manilagrass)

Zoysiagrass          Does not       2 to 3
(Mascarenegrass)     mow well

Grass
Species              Soil Tolerances           Climate Tolerances

Bahiagrass           Infertile, acidic,        Subtropical and
                     and sandy                 tropical

Bermudagrass         Does well on a            Warm temperate and
                     wide range of soils       subtropical

Bentgrass,           Moderately fertile,       Temperate and
Colonial             acidic, and sandy         seacoastal

Bentgrass,           Fertile, acidic, and      Subarctic and
  Creeping           moist                     temperate

Bentgrass, Redtop
  (see Redtop)

Bentgrass,           Moderately fertile,       Temperate and
  Velvet             acidic, and sandy         seacoastal

Bluegrass,           Fertile, neutral to       Temperate and
  Annual             slightly acidic           cool subtropical

Bluegrass,           Infertile, acidic, and    Subarctic and
  Canada             droughty                  cool temperate

Bluegrass,           Fertile, neutral to       Subarctic, temperate,
  Kentucky           slightly acidic           and cool subtropical

Bluegrass,           Fertile and moist         Subarctic and cool,
  Rough                                        shaded temperate

Bromegrass,          Infertile and droughty    Dry and temperate
  Smooth

Buffalograss         Does well on a            Dry temperate
                     wide range of soils;      and subtropical
                     tolerant of alkaline
                     soils

Carpetgrass,         Infertile, acidic, and    Subtropical and
  Common             moist                     tropical

Carpetgrass,         Infertile, acidic, and    Humid subtropical
  Tropical           moist                     and tropical

Centipedegrass       Infertile, acidic, and    Subtropical and
                     sandy                     tropical

Fescue,              Infertile, acidic, and    Subarctic and
Chewings             droughty                  temperate

Fescue,              Infertile, acidic, and    Subarctic and
  Creeping Red       droughty                  temperate

Fescue, Hard         Fertile and moist; not    Moist and temperate
                     tolerant to droughty
                     soil

Fescue, Meadow       Widely tolerant of all    Moist and temperate
                     but droughty soils

Fescue, Sheep        Infertile, acidic, well-  Dry and temperate
                     drained, and droughty

Fescue, Tall         Does well on a wide       Warm temperate and
                     range of soils            subtropical

Gramagrass,          Does well on a wide       Dry and subtropical
  Blue               range of soils

Redtop (a            Does well on a wide       Subarctic, temperate,
bentgrass)           range of soils            and cool subtropical

Ryegrass,            Fertile, neutral to       Temperate and
  Annual             slightly acidic and       subtropical
                     moist

Ryegrass,            Fertile, neutral to       Mild and temperate
  Perennial          slightly acidic and
                     moist

St. Augustinegrass   Does well on a wide       Subtropical and
                     range of soils            tropical seacoastal

Timothy,             Fertile, slightly         Subarctic and cool
  Common             acidic, and moist         temperate

Wheatgrass,          Does well on a wide       Subarctic and cool
Crested              range of soils            temperate

Zoysiagrass          Does well on a wide       Temperate, subtropical,
(Japanese            range of soils            and tropical
lawngrass)

Zoysiagrass          Does well on a wide       Subtropical and
(Manilagrass)        range of soils            tropical

Zoysiagrass          Does well on a wide       Warm subtropical and
(Mascarenegrass)     range of soils            tropical

                                               How Established. If
Grass                                          Seeded, Pounds Per
Species              Uses                      1,000 Square Feet

Bahiagrass           Utility turf; good for    Seeded at 6 to 8
                     use along roadways

Bermudagrass         Sunny lawn areas; good    Plugging or seeded at
                     general purpose turf      1 to 1 1/2
                     for athletic fields,
                     parks, home lawns

Bentgrass,           Areas where intensive     Seeded at 1/2 to 2
Colonial             cultivation is
                     practical

Bentgrass,           Golf greens and other     Sprigging or seeded at
  Creeping           uses where intensive      1/2 to 1 1/2
                     cultivation is
Bentgrass, Redtop    practical
  (see Redtop)

Bentgrass,           Shaded, intensively       Seeded at 1/2 to 1 1/2
  Velvet             cultivated areas

Bluegrass,           Not planted               Does not apply
  Annual             intentionally; but
                     common in intensively
                     cultivated turfs during
                     spring and fall

Bluegrass,           A soil stabilizer         Seeded at 1 to 2
  Canada

Bluegrass,           Sunny lawn areas; good    Seeded at 1 to 2
  Kentucky           general purpose turf
                     for athletic fields,
                     parks, and home lawns

Bluegrass,           Some use on shaded,       Seeded at 1 to 2
  Rough              poorly drained sites

Bromegrass,          A soil stabilizer         Seeded at 1 to 2
  Smooth

Buffalograss         Useful in semiarid        Seeded at 3 to 6
                     sites as a general
                     purpose lawn grass

Carpetgrass,         Utility turf; good for    Seeded at 1 1/2 to
  Common             use along roadways and    2 1/2
                     as a soil stabilizer

Carpetgrass,         Utility turf; good for    Seeded at 1 1/2 to
  Tropical           use along roadways and    2 1/2
                     as a soil stabilizer;
                     can be used as a lawn
                     grass in tropics

Centipedegrass       Utility turf; also        Seeded at 1/4 to 1/2
                     usable as a low-use
                     lawn grass

Fescue,              Shaded sites with poor    Seeded at 4 to 8
Chewings             soil

Fescue,              Shaded sites              Seeded at 3 to 5
  Creeping Red

Fescue, Hard         A soil stabilizer         Seeded at 4 to 8

Fescue, Meadow       Utility turf; good for    Seeded at 4 to 8
                     use along roadways

Fescue, Sheep        A soil stabilizer         Seeded at 3 to 5

Fescue, Tall         Utility turf; good for    Seeded at 4 to 8
                     use along road-ways;
                     new cultivars
                     (Brookston, Olympic,
                     and Rebel) good for
                     lawns

Gramagrass,          Utility turf; good for    Seeded at 1 to 2
  Blue               use along road-ways and
                     in arid sites

Redtop (a            Utility turf; good for    Seeded at 1/2 to 2
bentgrass)           use along road-ways and
                     in poorly drained areas

Ryegrass,            Useful for quick and      Seeded at 4 to 6
  Annual             temporary lawns in the
                     temperate zone and for
                     winter color in the
                     subtropic zones

Ryegrass,            Used in mixed species     Seeded at 4 to 8
  Perennial          lawns and as an
                     athletic turf

St. Augustinegrass   A good lawn grass with    Sprigging
                     excellent shade
                     tolerance

Timothy,             Utility turf; good for    Seeded at 1 to 2
  Common             athletic fields in cold
                     regions where
                     preferable species
                     won't survive

Wheatgrass,          Useful as a general       Seeded at 3 to 5
Crested              purpose turf on
                     droughty sites

Zoysiagrass          Useful as a general       Plugging
(Japanese            purpose turf for home
lawngrass)           lawns, parks, and golf
                     courses, especially in
                     warmer regions

Zoysiagrass          A good lawn grass         Plugging
(Manilagrass)

Zoysiagrass          A soil stabilizer and     Plugging
(Mascarenegrass)     groundcover
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Title Annotation:SECTION 2 Landscape Contracting
Author:Ingels, Jack E.
Publication:Landscaping Principles and Practices, 6th ed.
Date:Jan 1, 2004
Words:3564
Previous Article:Chapter 20 Installing landscape plants.
Next Article:Chapter 22 Lawn construction.
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