GARDEN COLUMN FOR THE SALISBURY POST
Darrell Blackwelder
August 17, 2001
 

     Much needed rain over the past few weeks has increased
unwanted grasses in lawns and flower beds.  The two most common
grassy weeds are bermuda grass and crabgrass.  The grasses are
prevalent and tend to over-take flower beds and thin areas of turf.
Bermuda grass and crabgrass should be eliminated before overseeding
in the fall.
    Bermuda grass, also known as cane grass, joint grass or devil
grass, is a perennial warm-season grass that thrives in hot
weather. This grass is often used on athletic field or play grounds
because of its ability to withstand wear.
     Bermuda grass often invades weak or thinned fescue lawns
during the summer months when fescue becomes semi-dormant. The
grass spreads by stolons (above ground stems) or rhizomes
(underground stems).  Roots form at the nodes or joints allowing
the grass to become well established over a short period of time.
Bermuda grass propagated itself from these specialized stems and
seed.  The seed or stems are often introduced in lawn or flower bed
by hauling in contaminated topsoil.
     Bermuda grass turns brown and becomes dormant after the first
hard frost.  The grass will remain dormant until the soil warms in
early summer. These "dead" patches of Bermuda grass give fescue a
spotty and unsightly appearance during the winter months.
     Many tell me every year that bermuda grass cannot be killed,
that they have tried with no success.  Bermuda grass is difficult,
but can be successfully eliminated in a lawn.
         Using a systemic herbicide containing glyphosate such as
Roundup is the only method of removing Bermuda grass from a lawn.
Bermuda grass must be completely eliminated before overseeding in
the fall. August is an excellent time to kill Bermuda grass in
fescue lawns.  The grass must be actively growing before the
herbicide will work.  Apply these herbicides while bermuda grass is
actively growing for complete kill. Bermuda grass must be irrigated
in drought situations to stimulate plant growth.
        It is important to have a complete kill of bermuda before
seeding in the fall.  It's almost impossible to have a 100 percent
kill the first spraying.  Save enough herbicide for areas missed
during the first spray. Bermuda will be back next June if you fail
to have a complete kill.
     Bermuda grass is also a pest in flower beds, shrubs and even
asphalt drives and walks.  Bermuda grass can be killed in shrub
beds without damage to the flowers or shrubs with over-the-top
sprays such as Vantage or Grass-B-Gone.  These are herbicides that
kill only grass and not broadleaf plants.
     Crabgrass is often confused with bermuda grass. It is a warm
season annual grass that also thrives in hot weather. Crabgrass has
exploded over the past few weeks with the increase in both
temperature and water. This grass adapts well and thrives in thin
or weak lawns. The seedhead of crabgrass is somewhat similar to
that of bermuda grass.  The leaf blades of crabgrass are wider than
the leaves of Bermuda grass.
     Crabgrass is an annual grass that grows as a bunch grass,
similar to fescue.  Crabgrass has a faint blue color to the leaf
blade.  A crabgrass plant produces thousands of minute seed which
remaining in the soil for years.
         Crabgrass dies with the first killing frost. Dead plants
can be raked and fescue can be seeded to fill the void, however
this may interfere with normal seeding in September.  Spot sprays
of herbicides containing glyphosate is recommenced to when
eliminating grass to overseed.
     It is important to remember that bermuda comes back each
season from underground stems.  Crabgrass is an annual and it
germinates from seed.  Prevention with preemergence herbicides is
the best control for crabgrass.  Bermuda grass must be completely
destroyed this month for reseeding fescue in the fall.  Be sure
Bermuda grass is dead before reseeding.  Your effort will be in
vain if the grass is not completely killed.