Evening star., 1952-06-15

OIle OI lne major lawn PROB
lens in the Washington area is
the tendency for the bluegrass to
weaken and disappear during the
heat Of the summer, and for crab
grass and weeds to take over.
Most lawn owners have a desire
for a green, velvety lawn from
early spring until late fall. Un-
fortunately, they seldom achieve
this ideal except in the early
spring, before crabgrass puts in
appearance, and in the late fall,
after froSts have put a stop to
the growth of most kinds of
weeds.
But in the heat of the summer
the bluegrass frequently tends to
weaken and the coarSe-appearing
crabgrass provides most of the
green. One of the reasons for
this lack of vigorous growth of
the bluegrass is the diseases that
attack, perhaps defoliate it. The
recently released variety of blue
grass. Merton. has a high resist
ance to these diseases.
Set Lawn Mower High.
However, it is possible through
better cultural practices for the
ordinary bluegrass to do a better
job. One of these is to leave
enough leaf surface on the plant
so that it can function and build
up a store Of food in the root
system. Close clipping greatly
reduces the plants ability to pro-
duce food. Moreover, there is
definite correlation between the
height of the blades and the depth
OF the root system. Close clip
ping thus reduces the size of the
root system. and because it is
small is highly subject to drought
conditions. The standard recon-
mendation for height of grass
during the summer is 2 inches.
Very few gardeners go that far,
but they should raise the cutter
bar to a height of not less than
Ia inches. Generally, students
Of lawn care advise setting the
lawn mower up by the middle of
May.
Most lawns should be fertilized
early In June to give the grass
plants push for good growth
during the summer. Perhaps we
might even skip the March feed
ing and concentrate on June
feeding in order to keep crabgrass
and weeds under better control.
There IS no better control for the
crabgrass than a good vigorous
stand OF bluegrass. Certainly,
with a wet cool spring, we did
not need March application of
plant food this pring to make our
grass grow.
Summer watering of lawns can
be beneficial or detrimental to the
growth of bluegrass. Frequent
waterings that do not wet more
than the top inch Of soil are of
benefit only to the crabgrass.
Bluegrass. to get some benefit
from the watering, sends its
roots up to the surface and burns
up the first time the soil dries out.
Watering during drought periods
should be done not oftener than
once week or 10 days. But when
water is applied to the lawn it
should be applied until the soil is
moistened to a depth of to 6
inches. Such a moisture supply
will reach down into the root area
and will benefit the bluegrass
and other deep-rooted lawn plants.
Mulching Beneficial.
Raking the lawn to pull out
crabgrass plants is seldom bene-
fetal to the bluegrass. This re-
moves every bit of dead grass and
mulching material that might
help to keep the surface of the soil
cool. 1t would help the growth of
the bluegrass to have a layer of
mulching material spread over
the entire area. Sifted compost,
moistened peatmoss, sawdust and
other available materials may be
used for this purpose.
Digging up the lawn to remove
crabgrasS and weeds too often in
jures the bluegress without effec-
lively removing the weeds. The
use of chemical weed-killers is
more likely to be effective. Po-
tassium cyanate is one of the most
effective of the crabgraSs killers.
1t is sold under various trade
names. so examine the label of
the proffered crabgrass killer for
the name of the killing agent.
For other weeds, 2, 4-D is still
one of the best that is readily
available. But, remember the
crabgrass and weed-killers work
best on a warm sunny day while
the weeds are young and in active
growth. Both of these materials