HOW TO
CONTROL WEEDS
IN YOUR
GARDEN
As soon as the weather warms up in spring,
you will find that
popping up with your blooming
bulbs are the unsightly weeds
that you had
wanted to get rid of past season.
There
are dozens of different kinds of herbicides
in the garden
store, but which should you choose?
The simplest but most labor intensive way is to
manually pull
and dig them out, root and all. For
those with bad backs, there
are several long
handled gadgets that are quite effective in
weed
removal without involving your back or your knees.
Some
weeds actually grow back more
vigorously by hand
pulling if you are not too
careful about removing the whole
root. Once
the tips are broken, the plant parts in the ground
may contain multiple buds. These will grow back
more
vigorous and thick. Field bindweed, purslane,
quackgrass
and dandelion are known to behave this
way.
To
effectively use herbicides, you must know if it
is a
perennial or an annual weed, whether it is
approved
for use on the lawn, around your trees
or your ornamentals.
Some herbicides work by
inhibiting weed seeds from
germinating; while
others work when the weeds are actively
sprouting.
2,4-D
is
effective on broad-leafed perennial weeds,
such as
dandelion, plantain and perennial chickweed.
Be careful when
applying this
because drift by wind
or air current to your broad-leafed ornamentals and
shrubs and trees can injure and kill
them too.
Some
broad-leafed weed killers are formulated and
marketed
with another product called Dicamba
(banvel). This is used
for hard to kill weeds such as
bindweed, thistle and oxalis. It
can leach in the soil
to
nearby plants, so careful spot application
is advised.
Both
2,4-D and
Dicamba have been shown to be
carcinogenic
in test animals. So before you reach
for
the sprayer, be
mindful of poisoning your
children and
pets who will be playing
on your lawn
that you had
sprayed.
There are several effective, non-toxic methods
of
weed control.
A natural,
pre-emergent, non-toxic
herbicide that kills germinating annual
weed seeds
is
corn gluten. It is totally safe to use
around
children and pets.
Other
than corn gluten are two synthetic,
pre-emergent herbicides that
you can find
in your garden store. These are herbicides with
formulations containing Dacthal (DPCA), Surflan,
or Ryzelan
(oryzalin).
DCPA
(Trade name Dacthal, chemical name
dimethyl
tetrachloroterephthalate) is
approved for
crabgrass and
broad-leafed weed control in turf,
flower gardens, fruit and
vegetable crops.
Surflan
is a pre-emergent herbicide
approved for control
of
annual weeds and crabgrass. Be aware that
Dacthal
contains 2 toxic impurities which are byproducts
during the manufacturing process.
These are
dioxin
and hexachlorobenzene, both
have been documented
as human
carcinogens.
A newer
product known as
Poast ( sethoxydim)
is
approved
for use around the lawn, trees, shrubs,
flower beds and
some fruit crops. This product is
a
post-emergent grass weed herbicide. It can be
used
when the
grass
weeds start to sprout.
For
areas away from vegetable beds and plantings
such
as along fences and buildings, you can spot-
treat
with
glyphosate (Roundup or Kleenup). This
is a kill-all
product.
These works best when weeds are actively
growing because
the growing shoot is most vulnerable.
Avoid rampant spraying.
It is not to be used in
areas
where you intend to grow plants
for eating.
If possible
avoid using this product because it is
highly toxic; and it
is persistent in the soil for at
least one year.
Other
weed killers that kill all are known by trade names as
Triox,
Pramitol and
Spike.
By state law, these can only be used by certified commercial
applicators. These
are so powerful that
application
of only a
few granules can penetrate and
migrate
in the soil to other untreated areas and kill
neighboring trees several yards away.
The most
important procedure in the use of weed killers
is to
read the label thoroughly and follow the directions
on the label. You must know beforehand what to do in
case you have an
accidental
exposure to the chemical.
Always
check what the active ingredient is. Get
a
magnifying
glass to see this, if you have to.
Do not buy
based on what
the marketing name
is. You may end up
with different bottles,
all with
the same active ingredient.
The trade name and the
scientific name on the
label in
active ingredients list tell you
what chemical you are dealing
with. To make it confusing, the
same chemical can
have
different names given by different manufacturers.
Manufacturers may also
combine two or more herbicides
in the same formulation to boost killing
spectrum
and activity;
and give it a new marketing name.
If you
are not sure what kind of weed problem you have,
there
are several good web sites with
beautiful photos to
guide you in
identification.
For
effective control, it is important to know which
is the
best
herbicide to kill the weed you want to control, whether
it is for pre-emergent or post-emergent use, the stage of
growth for
maximum control and the effective concentration.
Before
deciding to apply herbicides to your garden
or lawn,
consult your State/County Extension Office web site or call
them. They are there to help you.
Reference:
Weed Control for the Garden and
Landscape.
http://www.hort.purdue.edu/ext/HO-217.pdf
