Active Ingredient

the ingredient in a product that is biologically active, the ingredient in a product that does the job the product is intended to do


the process of perforating soil in order to allow air and water to penetrate built-up grass or lawn thatch




an underground layer of water-bearing permeable rock or unconsolidated materials from which water can be extracted using a water well


chemical commonly used in broadcast tick sprays, also toxic to fish


a chemical substance or microorganism which can deter, render harmless or exert a controlling effect on any harmful organism by chemical or biological means

Broadcast Tick Sprays

tick treatments used to cover a large area, usually containing harmful chemicals such as permethrin or bifenthrin


formulations which can be applied to plants to improve vigor

Beneficial Organisms

bacteria, fungi and arthropods in soil that break down organic matter into nutrients for plants or they can be insects which are beneficial to landscape health by eliminating pests or performing other beneficial functions. Often these beneficial organisms can be killed unintentionally by treatments targeting pest species or other harmful chemical treatments

C:N Ratio

carbon to nitrogen ratio, used to evaluate soils and composts


chemicals that cause cancer due to mutagenic effects resulting from exposure

Certified Applicator

certain pesticides (restricted use) cannot be used unless they are applied by a certified applicator who receives training and certification according to national standards

Chromobacter Subtsugae (Grandevo)

Bacterium which can be used as a pesticide

Compacted Areas

areas of a lawn that receive a lot of foot, vehicle, wheel or other traffic become compacted, which doesn't allow for proper air and water movement through the soil. Can be remedied by aeration

Conventional Pesticide

any man-made chemical which can be used to kill pests


commonly used as a fungicide, insecticide or sporicide, creosote is produced by burning organic materials and can have a range of adverse effects on human health


The grass crown is the thick, whitish part of the turf grass that grows at soil level where grass shoots and roots meet

Damping Off

a disease or condition, caused by a number of different pathogens that kill or weaken seeds or seedlings before or after they germinate, most common in wet and cool conditions

Dappled Light

irregular or spotty lighting, such as would be produced by sunlight shining through tree branches


the community of living things in conjunction with non-living components of the environment all interacting as a system

Effective Neutralizing Value

the ability of a unit of lime to change the pH of soil

Endocrine Disruptors

chemicals that may interfere with the bodies endocrine system and produce abnormal developmental, reproductive, neurological and immune effects in both humans and wildlife


An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life without causing apparent disease

Entomopathogenic Nematodes

very tiny worms which can kill harmful insects such as grubs


the process by which nutrients are added to a body of water, which can occur through runoff of fertilizers and other processes, and often results in the excessive growth of algae


a chemical used to kill fungus


the property of a chemical agent which damages genetic information within a cell causing mutations, which can lead to cancer


the process by which a seed grows into a plant


a broad-spectrum systemic herbicide used to kill weeds, especially annual broadleaf weeds. Commonly found in commercial weed killers like Roundup

Growing Degree Days

measure of heat accumulation rates which are used to predict plant development


bird or bat excrement which can be used as an organic fertilizer


when a plant exudes drops of xylem sap on the tips or edges of the leaves of vascular plants such as grasses, occurs under wet conditions


dark organic material that forms in soil when plant and animal matter decays


a widely used organophosphate insecticide that can have a range of human health effects


any living organism that is too small to be seen with the naked eye, can include bacteria, protists and fungi


substances that kill mites


vegetative part of a fungus composed of a mass of branching, thread-like hyphae (branching structure of fungus)

Neem Oil

a vegetable oil extracted from the seeds and fruit of the neem tree which can be used to fight common lawn pests


a type of chemical pesticide used to kill plant-parasitic nematodes


when exposure to a natural or artificial toxic substance alters the normal activity of the nervous system, resulting in damage to nervous tissue

Nitrogen Fixation

the process, commonly carried out by clover and legumes, by which nitrogen is broken down so it can be used as nutrition for plants

Organic Matter

the "fuel" of the soil food web, made up of both active and inactive organic material

Organophosphate Insecticides

some of the most common and toxic insecticides, can damage the human nervous system

Perched Water Table

an aquifer that sits above the regional water table due to the presence of an impermeable surface above the main water table


chemical commonly used in broadcast tick sprays, also toxic to fish

Physiological Drought

condition where a plant is not able to take in water, not because it is unavailable, but due to a range of possible conditions preventing absorption of the water

Phytotoxicity Test

test to determine the toxic effect a compound has on plant growth

Pre-Emergent Herbicides

prevent the germination of seeds but will not harm any established plant, commonly used in "weed and feed" fertilizers


plant parasite which can cause disease in plants like root rot




a chemical that causes a substantial portion of exposed people or animals to develop an allergic reaction in normal tissue after repeated exposure

Slow-Release Fertilizers

release nutrients to plants gradually to allow plants to better absorb them, making them more efficient and less likely to run off into water supplies


a specialized type of horizontal, above-ground shoot. Also known as runners


minute structures on the outer leaf structure of plants that allow for the exchange of gasses


To pack down a substance, such as dirt, into a more solid form



Top dressing

application of compost or fertilizer to the surface layer of soil

