Environmental Engineering Reference
In-Depth Information
Poa pratensis
L. is the most widely used of the cool-season turf-grasses
throughout the world. It can be found on lawns, golf courses, cemeteries,
parks, school grounds, athletic fields and other areas where a dense grass
cover is desired.
Poa pratensis
recovers from injury quickly and spreads
very fast. It develops a dense turf, has excellent colour and is easy to
mow. It tolerates low temperatures and many diseases. During periods of
drought, it undergoes dormancy but easily survives and can quickly
regain its colour when water becomes available. When mowed at the
correct height, 50-70 mm, it competes very successfully with weeds.
Disadvantages of this species include its shallow root system, rela-
tively high demand for water and poor tolerance of shade. Hundreds of
P. pratensis
cultivars have been developed around the world. Old, com-
mon types are well adapted to lower-maintenance conditions. New,
improved cultivars are suitable for high-maintenance turfs.
Poa trivialis
L. is used in cool, humid regions in wet, shaded areas
along rivers and lakes and where conditions are too shady for
P. pratensis
.
It does not tolerate traffic or drought well.
P. trivialis
is sometimes used
for winter overseeding of dormant cynodon turf (see Turf-grass Commu-
nities, later in this chapter).
Poa annua
L. (annual blue grass) has the widest geographic distribu-
tion among grasses. It is often considered a weed, but in some countries it
has become so dominant, and the possibility of eradication so remote,
that it is used as the primary turf species. It can be found nearly every-
where in the world except the humid tropics. Its extraordinary success is
related to the timing of its germination. Unlike other weedy grasses,
which germinate in the spring,
P. annua
germinates in the late summer
and early autumn; it lives through the winter as a mature plant and then,
after producing seeds in the spring, it dies. Annual blue grass is particu-
larly well adapted to low mowing heights, and it is on closely mown turf
that it generally becomes a problem.
Other
Poa
species, of minor importance as turf-grasses,
include
P. supina
Schrad.,
P. compressa
L.,
P. bulbosa
L. and
P. alpina
L.
The genus Festuca (Festucoideae)
The genus
Festuca
includes more than 360 species that differ widely in
appearance. Less than ten species are used as turf, all in cool climates.
Festuca arundinacea
Schreb., tall fescue, is a deep-rooted, cool-season
perennial grass. It produces vigorous growth in spring and autumn, and its
extensive root systemhelps it withstand drought conditions. The species is
adapted to a wide range of soil and climatic conditions, but performs
best where winter is rather mild. Its requirement for relatively high
mowing limits its use to lawns, parks, golf course roughs and other areas
mowed at 40 mm or more. Proper, frequent watering is important to its
