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alternatives to pesticides - weeds

What is a weed?
A plant whose virtues have
not yet been discovered.

– Ralph Waldo Emerson

Blackberry             Bittercress          Clover          Dandelion
Horsetail rush       Morning glory      Moss            Poison oak
Quackgrass           Thistles

Identify the problem
Before considering what control measure to use, correctly identify the weed you are facing. Nursery personnel are a good resource, as are many books in garden stores and the library. WSU Cooperative Extension Master Gardeners or a county extension agent can be helpful.

Use appropriate controls
The choice of controls for weeds depends on the problem. Generally, options fall into the categories of hand removal and/or least-toxic chemical control. Once you understand how each tactic works, you can make informed decisions on their best use.

Least-Toxic Chemical Controls
Although using the practices mentioned previously will minimize, and possibly eliminate, the need for pesticides, there may be times when you choose to use them. In order to make informed decisions, it is important to understand them.

A few words about toxicity

All pesticides (synthetic and organic) are, by definition, toxic to some living thing – insecticides to insects, herbicides to weeds, fungicides to fungi, and so on. When a pesticide or any other material is described as “toxic,” it often makes people think of the effects the material has on human health. However, pesticides (and other chemicals) can also have toxic effects on the environment in which they are released.

There are many different ways to describe the toxicity of a material. For example, toxic effects on living organisms can be either acute (occurring immediately after the material is ingested or absorbed) or chronic (occurring after long-term exposure to the material). A substance may be short-lived (breaking down to harmless elements in a matter of hours or days) or persistent (remaining in their original state for months or years).

Materials may bind readily to soil (making them more likely to remain in the site where they were applied) or may be very mobile (making them more likely to travel into surface or groundwater). Still others may be very soluble (dissolvable in water), volatile (likely to explode), or flammable (able to burn). In addition, some can cause secondary poisoning (direct or indirect effects on other living things that eat the original target).

Is “organic pesticide” an oxymoron? How about “synthetic organic?”
Ask a chemist what “organic” means, and he or she is likely to say, “Contains carbon.” All living things contain carbon, so organic matter is simply the stuff that at one time was part of a living plant or animal. Some fertilizers and pesticides can be produced from animal and plant parts, thus they can be called organic as well. The word “synthetic,” when referring to garden products, means “created by humans: not occurring in nature.” Synthetic pesticides are chemical compounds invented in a laboratory.  Ironically, those synthetic compounds that contain carbon can, technically, be called “synthetic organic.” 

Note that although the word organic, when it is used to describe the way foods are grown, has come to imply “pesticide-free,” a more accurate definition of the term in this case might be “grown without synthetic pesticides.” Note also that some pesticides are not derived from plants or animals yet are still considered safe to use, and they are allowed in organic food production. Examples include insecticidal soap, horticultural oil, copper and sulfur.  The bottom line is this: no pesticide, synthetic or organic, is considered “safe.” But, because of the effects on other living things, some are safer to use than others.

Read the label. Before selecting a pesticide, become informed about all the effects it may have.

Use it properly once you purchase a pesticide.

Dispose of Household Hazardous Waste Safely. Because pesticides are hazardous, they should never be disposed of in your garbage can or poured down the drain, into storm drains or onto the ground. In Clark County, call Environmental Services at 397-6118, ext. 4016 for more information for information about

Banned or Restricted Pesticides
Pesticides include insecticides, herbicides, fungicides and rodenticides, which are designed to kill insects, weeds, disease and rodents. Using pesticides may be necessary at times, but in many cases there are alternatives that are often more effective in the long run and less harmful to public health and the environment. If you choose to use a pesticide be aware that a number of pesticides that were once legal to use are now banned or restricted from household use. Some of the pesticides you should NOT use are: Aldrin, Arsenates, Benzene Carbon Tetrachloride, Chlordane, Creosote, DBCP, DDT, Diazinon, Dieldrin, Heptachlor, Kepone, Lindane, Mirex, Pentachlorophenol (PCP) Silvex, Sodium Arsenite, Sodium Cyanide, 2,4,5-T, Toxaphene, and Vinyl Chloride.

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