Pesticides are chemicals used to kill or repel pests.
Pesticides include herbicides (which kill plants), insecticides (which kill insects), and fungicides (which kill
The pesticides used in a yard may pose a health
threat to the person applying them if not handled carefully and properly. They may also pose a threat to animals,
plants and insects beyond the intended pests. Honeybees are an example of a nontarget organism. Bees are
very susceptible to many household pesticides such
as carbaryl (Sevin). Other nontargets include ladybird
beetles, which are a natural biological pest control, and
fish, which can suffer direct poisoning from the household insecticides permethrin, resmethrin, pyrethrin, and
rotenone washed into a stream or lake.
Chemicals we apply to the land surface can affect
the groundwater. Contamination may occur when polluted surface water moves through the soil to the water
This fact sheet describes a variety of non-chemical
methods of pest control. It also provides tips for using
pesticides in an environmentally sound way.
Integrated Pest Management
When we see weeds or insects invading our favorite plants, our first response is often to apply a pesticide.
Some people even apply a pesticide to prevent invasion
by pests. Both of these automatic responses lead to unnecessary pesticide use. A better approach is Integrated Pest Management (IPM).
IPM is an ecological approach to pest management
that integrates cultural, mechanical, biological and, as a
last resort, chemical control methods.
Steps to follow in IPM:
1. Learn about plants and their pests.
2. Select the right plant for the location.
3. Frequently inspect plants to see if pest levels are
increasing or decreasing. Usually, each plant species will be attacked by only a few insect pests and
4. Identify pest symptoms. Knowledge of pests, their
life cycle and the damage they cause is essential for
effective pest management.
5. Determine if control measures are really needed.
For example, this can be determined by counting
the number of insects present and looking carefully
at the amount of damage they are causing. Most
plants can tolerate a considerable amount of feeding by insects before any serious damage occurs.
6. When treatment becomes necessary, select methods
that are least disruptive to natural controls and least
hazardous to human health and the environment.
Start with cultural, mechanical, or biological controls.
7. Evaluate your treatment to see which methods
Cultural pest control methods attempt to create
optimal growing conditions for plants and unfavorable
conditions for pests.
• Select disease-resistant varieties.
• Plant varieties adapted to the geographic and soil
• Maintain a rich, fertile soil, with the proper pH for
the plants being grown.
• Rotate vegetable garden plants to disrupt the life
cycle of pests (called crop rotation).
• Plant and harvest early to promote healthy, strong
plants and avoid peak insect populations.
• Remove pest-infected plant residue in the fall.
• Plant a wide variety of crops to reduce potential
pest problems (known as crop diversification).
• Evaluate plant success against water required
during the growing season and the availability of
sunlight. Most garden plants need plenty of each to
help control pest problems.
For Lawns (mow as high as possible)
• Proper mowing heights are important and need to
be set according to the publication,
MF-1155, Mowing Your Lawn.
Mow often, each time the
grass reaches 3 to 4 inches. (It’s important not
to cut more than
one-third of the
height). • On troublesome spots, remember that improper
light, moisture or soil conditions discourage good
turf. Use of shade-tolerant grasses, bringing in topsoil, or switching to alternative groundcovers may
be the key.
A number of organisms feed on or infect insect
pests. These biological controls frequently prevent the
insect population from reaching damaging levels. Three
types of natural enemies are:
• Predators – such as ladybird beetles, ground beetles
and birds that consume many pests in their lifetime.
• Parasites – such as the trichogamma wasp, which
will generally consume one individual insect pest
during its own lifetime.
• Pathogens – such as fungi, bacteria, and viruses,
which infect many insect pests simultaneously.
Minimizing the use of pesticides on lawns and
gardens allows these natural enemies to thrive, helping
to keep pest populations in check.
• Practice the vanishing art of hand-weeding. When
health, expense, environmental consequences, and
even time are considered, small problems with
lawn weeds are handled in no better way.
• Use tillage of the soil in weedy areas, rather than
• Like hand-weeding, a few large insects (such as
certain caterpillars) may be easily removed by hand
in little time and at no expense, or environmental or
• Use mulches to reduce weed problems, conserve
moisture, and prevent soil erosion.
When you have accurately identified a pest in damaging numbers (above the plant’s tolerance threshold),
and other controls have failed or are impractical, carefully choose a pesticide. Pesticides are usually effective
only during certain stages of a pest’s life and at specific
concentrations. If possible, select a pesticide that is
“pest-specific,” that is, designed to kill only the insects,
weed and disease organisms causing the damage. Less
toxic pest control products are available and include:
• Microbial insecticides – Those derived from microorganisms such as Bacillus thuringiensis.
• Inorganic insecticides – Some oils and soaps kill
pests on contact and pose little threat to the environment. Insecticidal soaps destroy pest membranes and are effective against soft-bodied insects.
Note: Botanical pesticides derived from plants,
such as rotenone, nicotine, ryania, pyrethrum, and
sabadilla may not be any safer to people or nontarget
organisms than many synthetic insecticides. They are,
however, short-lived and break down quickly in the environmentPesticide Application
Use pesticides only when other control methods
fail. Extensive use of pesticides can kill beneficial organisms that help keep pest populations under control.
• Read the label carefully – it tells how, when, and
where to use the product.
• Apply the amount specified on the label and apply
only to the plants and areas listed. Over-application
is a waste of money and an environmental hazard.
• Wear protective clothing as directed on the label.
Do not wash clothing contaminated with pesticides
with other clothing.
• Make sure the pesticide is designated for use on the
pest you want to control.
• Do not mix different pesticides unless instructed by
the product directions.
• Keep pesticides in their original containers, so you
know what they are and how to use them. (This is
• Do not apply pesticides if rain is imminent (unless
specified on the label). Some pesticides do need to
be watered-in after application, but rain or watering
can wash others off plants, decreasing effectiveness, and contaminating lakes and streams. (Read
• Never spray pesticides on breezy days. The spray
drifting in the wind poses a serious danger to nontarget plants and animals — including those in the
• Never apply pesticides to highly erodible areas.
When it rains, pesticides can easily be washed off
these sites with eroding soil.
• Never apply pesticides near wells, streams, ponds
or marshes unless instructions specifically allow for
such uses.Pesticide Storage and Disposal
• Don’t buy more pesticide than you need. Disposal
can be a problem.
• Store pesticides where children and pets can’t get
• Never dispose of excess pesticides by dumping
them on the ground. While pesticides are broken
down to nontoxic compounds by microorganisms,
excessive amounts applied to the soil can “overload” this natural system. They can contaminate
• Consider sharing leftover pesticides with neighbors, as long as they have a properly diagnosed
pest problem that is not easily treatable through
• Never dispose of unwanted pesticides in the ditch,
gutter storm sewer or toilet. Such practices allow
the hazardous chemicals to move directly into
streams and lakes where they can harm fish and
wildlife. In addition, pesticides dumped down the
drain can kill beneficial organisms that help purify
the waste water in treatment plants of a septic system.
• Take advantage of your designated pesticide collection site.
• When a pesticide container is empty, fill it with
water three times, each time pouring the rinse water into the spray tank when preparing the solution
for final application. Triple-rinsing is important,
because some chemical residues may remain in a
container even though it appears empty.
• Dispose of empty, triple-rinsed pesticide containers
as instructed on the label. Small containers can be
wrapped in layers of newspaper or in a plastic bag
and placed in the garbage on the day of pickup.
Never burn or bury empty pesticide containers.
The fumes from burning pesticide residues may be
toxic. Buried containers could leak pesticides into
Thinking Twice and Acting Sensibly
When pests invade lawns and gardens, consider the
full range of pest control options. In many cases, pesticides will not be necessary. When pesticides must be
used, follow label directions carefully to minimize harm
to people and beneficial plants and animals.
For more information on alternative pest control
methods and proper application of pesticides, contact
your local K-State Research and Extension office.