Glossary
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
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
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
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
Crown
The grass crown is the thick, whitish part of the turf grass that grows at soil level where grass shoots and roots meet
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
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
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
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
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
Phytotoxicity Test
test to determine the toxic effect a compound has on plant growth
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
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