General Terms

Active Ingredients

This is on the label under the chemical nomenclature. It tells you how concentrated the chemical in the percent of active ingredient The remainder is inert ingredients used as a carrier which could be water, solvents, clay, etc. The higher the percent active ingredient, the more concentrated the product. So it is a good comparison figure when you purchase products.

Beneficial Insect

Insects that eat or lay their eggs in other insects thereby controlling them.

Chemical Name

Most pesticides are normally sold under 3 different names. The trade name is the one that is the best known and usually is the one which buying decisions are made. The other two are the generic name and the long chemical name (which is in the small print with the active ingredient). The generic name and chemical name are good names to use when comparing like products, since they will be the same on all products that have the same active ingredient regardless of what trade name it is sold under. For example, Weed Impede (trade name) which is oryzalin (generic name) and 3,5-dinitro-N4,N4-dipropylsufanilamide (chemical name) which is 40.4% active ingredient. With this information you can compare other products that have oryzalin as the active ingredient. See also Types of Plant Protection and Fertilizers.

Cool Season Grass

Grasses that remain green all winter long in mild, climate areas.


Letting your spray get where you don't want it, usually because of wind or poor application technique.


This is how a chemical is produced and packaged. It is a carrier for the active ingredient. Dry formulations are WP (wettable powders) WDG (water dispersible granules) for mixing with water and dusts or granules for using as is. Liquid formulations are EC (emulsifiable concentrates), SC (soluble concentrates), flowables (suspensions) and AS (aqueous solution) to name a few. These are normally produced different ways to get insoluble, active ingredients to mix with water.


Product for control of weeds


Usually referred to with herbicide use, which means to mix into the soil.


These are the elements needed by plants to maintain growth. Without them, the plant can't live. They are needed in small amounts and too much can cause toxicity. Examples are Iron, Copper, Zinc, Magnesium, Calcium, Sulfur, etc.

National Organic Program (NOP)

The NOP is a regulatory program housed within the USDA Agricultural Marketing Service. They are responsible for developing national standards for organically-produced agricultural products. These standards assure consumers that products with the USDA organic seal meet consistent, uniform standards. The NOP logo in for home gardeners is three green leaves next to the words, “For Organic Gardening”.

OMRI- Organic Materials Review Institute

This national nonprofit organization produces a list of which input products are allowed for use in organic production and processing. OMRI Listed—or approved—products may be used on operations that are certified organic under the USDA National Organic Program.

Pre Harvest Interval

This is for edible fruits and vegetables and refers to the time between the last application of the product and when it can be harvested and consumed.


Refers to the period other material must be on the plant before a rainfall or irrigation to retain its effectiveness.


Product designed to control rodents such as mice, rats, gophers, squirrels. etc.

Warm Season Grass

Grasses that go dormant in the winter in mild climate areas. They normally will not grow in cold winter areas.


A plant growing where it is not wanted. This could be a flower or a tree.


Contact Herbicide

A herbicide that only kills the plant material it is sprayed on. They will not kill the root systems.


Non Selective Herbicides

Controls the plant material it is sprayed on. See also Selective Herbicide below.


Preemergence Herbicide

Controls weeds as they germinate. Most will not control emerged weeds.


Postemergence Herbicide

Controls weeds that are out of ground. Most have no soil activity.


Residual Herbicides

Generally, a preemergence that stays in the soil for a specific amount of time to prevent weed germination.


Selective Herbicide

Many herbicides are selective in what they control. That's why we can take broadleaf weeds out of your lawn or, control grasses in your flowerbeds. See also Non Selective Herbicide above.


Systemic or Translocated Herbicide

These are herbicides that are taken up by the plants through the leaves and moved throughout the plants system killing the entire plant, roots and all.


Oil Concentrate

This term is often used to describe and adjuvant that is added to the spray mix to improve performance of herbicide (weed killer) products. Oil concentrate products are sometimes referred to as “Spreader-Stickers” or “Penetrants” when used to help the herbicide adhere to the weed surface and penetrate into the weed for better uptake. Monterey Herbicide Helper is an example of an oil concentrate product that is recommended for use with Grass Getter and Nutgrass Killer II herbicides.