There are three major types of cool-season grasses: bluegrasses,
fescues, and ryegrasses. Bentgrass is another
type, but it requires more maintenance and is not as adaptable as the
others are to various climate zones; it is used primarily on golf
greens and in the Pacific Northwest.
The blades of bluegrasses all have a characteristic boat shaped tip,
with the edges curved up like the sides of a canoe. Most are relatively
cold tolerant but need generous amounts of water and fertilizer. Kentucky bluegrass is the most popular; rough bluegrass is often added to shade mixtures.
Creeping Bentgrass
Agrostis palustris
Used extensively in cool climates for golf
course putting greens and tees, lawn bowling greens, grass tennis courts, and
some home lawns. It produces a fine-textured, soft, very dense, carpet-like
lawn. However, it must be carefully tended or it can quickly lose its attractiveness.
It requires frequent watering, low mowing and high requirement fertilizing (1/2
to 1 pound of actual nitrogen per 1,000 square feet per month of active growth.)
While it is susceptible to a wide range of diseases, some cultivars
that are quite resistant include "Penncross", which is dense, disease resistant,
and quick to recover from damage; "Providence", which is darker green and has
more of an upright growth habit; "Seaside", "Cobra", "Emerald", "Penneagle",
"Pennlinks", "Prominent", and "Putter".
Kentucky Bluegrass
Poa pratensis
The most widely planted cool-season grass, especially in the northern
latitudes. Blue-green in color, medium to fine textured, and very cold hardy,
it represents the standard for appearance against which other cool-season
grasses are measured. It is widely used for lawns, athletic fields, golf fairways,
and general-purpose turfs because of its beauty. Even so, it requires conscientious
maintenance. It is best adapted in northern states east of the Rockies, in
the Pacific Northwest, and at higher elevations in the South. Mow it to between
11/2 and 21/2 high, slightly higher during hot weather. Water frequently and
fertilize generously. Among the most useful cultivars
is "Adelphi", which is low growing, dark green, and fine leafed; it is especially
disease resistant, fairly tolerant of shade and heat, and attractive even
under low maintenance.
Rough Bluegrass
Poa trivialis
A bright green, fine-textured, and shallow-rooted
grass with boat-shaped tips to its blades, this relative of Kentucky bluegrass
is noted for its high tolerance of moist soils and shade. The grass is soft,
cold hardy, and retains its color over winter in mild climates. It makes a
good component in shady-lawn mixtures, but in sunny areas it tends to crowd
out other worthwhile grasses, particularly Kentucky bluegrass and perennial
ryegrass. Most rough bluegrass is grown in the same locations as in Kentucky
bluegrass. Popular cultivars are "Colt",
"Laser", and "Sabre".
Fine Fescues
Festuca species and varieties
Includes chewings, hard, and red
fescue, all very fine leafed grasses that are used extensively in seed
blends for both sunny and shady situations. They germinate rapidly (7
to 14 days) and establish themselves quickly. They are medium green in
color and spread by tillers or short creeping rhizomes. During extended
hot, dry periods, fine fescues may lose their color rapidly.
Chewings fescue
Festuca rubra commutata
An aggressive, bunch-type fine
fescue that can overtake other grasses - a bad quality if you want to
preserve these but good if you want to crowd out weeds. Because of its
high shade tolerance, it is sometimes used to overseed shady lawns,
often in mixtures with perennial ryegrass. Chewings fescue is best
adapted to cooler areas in the northern United States and Canada, the
coastal regions of the Northeast and Pacific Northwest, and elsewhere
where summers are cool. It is well adapted to the sandy, acidic, often
infertile soils that are found in these regions.
Hard Fescue
Festuca ovina var. duriuscula
A fine-textured grass found mostly in the
northern United States and Canada and at high elevations. Growing in clumps,
it is slower to fill in and become established than chewings and red fescue,
but it needs minimal maintenance when mature. It is tolerant of shade in well-drained
soils and is fairly drought resistant and salt tolerant. Highly resistant
to diseases such as dollar spot, leaf
spot, and red thread, it is generally healthier
than other fine fescues. It also stays greener over summer, even during extended
dry period. Its wear ability is fair, though the clumps do recover slowly
from damage.
Red Fescue
Festuca rubra
Also called creeping red fescue, it is
a frequent component of bluegrass mixtures. A fine-textured grass with narrow,
dark green blades, it blends well and does what some bluegrasses cannot -
it grows well in both shade and drought. Red fescue is preferable to chewings
fescue in a seed mixture because it is more heat tolerant and less likely
to form thatch. It is best adapted where
summers are cool, such as in the coastal Northwest and at high elevations.
It is widely planted in the Great Lakes region. It grows well on banks and
slopes and creates an especially lush effect when left unmowed.
Tall Fescue
Festuca arundiacea
A dense clumping of grass that
forms a coarse turf able to grow in sun or shade, this species stays
green all year in mild-winter climates. It is a good general grass for
home lawns as well as for playing fields and commercial grounds. Its
disadvantages are its coarse texture and clumping style of growth. It
does best in areas of mild winters and warm summers, and in
mild-temperature regions of the Southwest.
Annual Ryegrass, Italian Ryegrass
Lolium multiflorum
A cool-season annual or, in
cooler climates, a short-lived perennial bunch-type grass. It forms a
medium to coarse-textured lawn with moderate wear resistance. In
temperate climates, it is sometimes used as a temporary lawn in late
spring. In mild-winter areas of the southern, southwestern, and Pacific
states, it is often used to overseed dormant warm-season grasses for
winter color. Best grown in full sun, this grass requires a moderate to
large amount of water and is not drought tolerant. It also has poor
tolerance of heat and cold.
Perennial Ryegrass
Lolium perenne
Deep green glossy leaf blades, a
shallow root system, and a texture that is finer than annual ryegrass
characterize this grass. Exhibiting the best wear tolerance of any
cool-season grass, it is often used as a tough play lawn. However, its
intolerance of extreme heat, cold, and drought make it best adapted to
coastal regions with mild winters and cool, moist summers. In southern
states, it is sometimes used instead of annual ryegrass to overseen
dormant lawns of warm-season bermudagrass during winter. But unlike
annual ryegrass, it tends to persist during the transition from cool to
warm weather - a disadvantage if you want the bermudagrass to
predominate again when summer returns. Perennial ryegrass likes full
sun but will tolerate some shade. Its non-creeping, bunchy-type growth
forms a uniform lawn if the grass is properly established and
maintained.
