Controlling Weeds and Using
Herbicides Safely
June 2002
By Mary Bernard, Master Gardener
Weeds in the landscape
are a perennial nuisance for most gardeners.
A variety of weed management options are available to help deal with the
problem. The choice of a specific weed management
program depends on the weeds present and the types of turf or ornamentals
planted in the area.
There are also
considerations regarding public concern about the use of chemicals to control
weeds. Because of the many variables,
weeds in landscape plantings are often controlled by a combination of
non-chemical and chemical methods.
Non-chemical methods for
managing weeds in the landscape and home garden help to minimize the need for
chemical weed killers. These include mechanical
control measures such as hand weeding, hoeing, cultivating, and mowing or
physical controls such as the use of mulches, landscape fabric, or black
plastic. Non-chemical methods are generally safest and
pose the least amount of risk to the environment.
If used properly,
herbicides can be safe and very effective, but the home gardener should use
them with extreme caution. Herbicides
are designed to kill plants and can injure desirable species that are exposed
to them. Injury is most likely when
label directions are not followed, such as applying excessive rates. Herbicides may cause damage if droplets drift
during application, when warm weather causes herbicides to vaporize, or if
roots of non-target plants grow into treated soils. Herbicides contained in some “weed and feed”
products can severely damage or kill broadleaf trees and shrubs growing near
treated lawns. These products can also
pose serious environmental problems, as they can become groundwater pollutants
where overused.
If you decide to use
herbicides follow these tips for best results:
·
Correctly identify the target weeds. Be sure that you select the right herbicide
product for your specific weed problem.
Consult a knowledgeable professional if you are in doubt.
·
Read and follow the label instructions.
·
Make sure that you understand how much to use, how and when
to use it, how long it lasts, which ornamental plants or locations it is
registered for, and what weeds it kills.
Do not use more than the recommended rate.
·
Always use caution when handling any garden chemical. Wear proper protective gear.
·
If you mix your own herbicide solutions, estimate the size
of the project or area to be treated. Do
not mix more chemical than can be used up to complete the project. As a rule, do not store mixed herbicide for
more than 24 hours as it will begin to breakdown and lose its effectiveness.
·
Keep children and pets out of treated areas until the
herbicide is incorporated, is irrigated into the soil, or until it has dried.
·
Make sure the sprayer is working properly. Keep a separate sprayer just for herbicide
use to avoid damage to non-target plants from herbicide
residue remaining in the sprayer.
·
Avoid using herbicides when it is windy to avoid damage to
non-target plants. Don’t spray if leaves
on plants nearby are fluttering.
·
Store unused herbicides in their original labeled container
in a locked storage area.