Glossary


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

Aeration

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

Alkaloids

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms

Aquifer

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

Bifenthrin

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

Biocides

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

Bio-stimulants

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

Carcinogens

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

Creosote

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

Crown

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

Ecosystem

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

Endophyte

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

Eutrophication

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

Fungicides

a chemical used to kill fungus

Genotoxicity

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

Germination

the process by which a seed grows into a plant

Glyphosate

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

Guano

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

Guttation

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

Humus

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

Malathion

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

Microbe

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

Miticides

substances that kill mites

Mycelium

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

Nematicide

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

Neurotoxicity

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

Permethrin

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

Pythium

plant parasite which can cause disease in plants like root rot



Rhizomes

a rhizome is a modified subterranean stem of a plant that is usually found underground, often sending out roots and shoots from its nodes



Sensitizers

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

Stolon

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

Stomata

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



Tamp

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

Thatch

a tightly bound layer of dead grass, including leaves, stems, and roots, that builds up on the soil surface at the base of the living grass of a lawn

Top dressing

application of compost or fertilizer to the surface layer of soil



Watershed

the area of land where all the water that falls in it and drains off of it goes into the same place