Aeration The practice of improving the movement of air, water, and nutrients into the soil by making holes or slits in it. Specialized machines are commonly used to remove plugs of soil or cut slices in the soil.

Annual Annuals are flowering plants that last only one season.

Biennial Biennials are plants that grow for one year without flowering, produce flowers/fruits in the second year and die.

Compaction An unfavorable soil condition caused by mechanical forces such as heavy traffic. The soil particles are pressed closely together, and pore space is eliminated form the soil.

Complete Fertilizer A fertilizer product that contains nitrogen, phosphorus, and potassium.

Cool Season Turfgrass A turfgrass species that grows best when temperatures are in the 60 – 75 °F (15 – 24 °C) range.

Deciduous Trees Trees that shed foliage/leaves at the end of growing season.

Dethatch To reduce an excessive thatch accumulation, usually with a machine such as a vertical mower.

Disease An abnormal, unhealthy condition caused by pathogen such as fungi, bacteria, and nematodes that results in injury to the grass plant.

Dormancy A resting stage during which a plant’s growth rate is greatly reduced because of extended drought, heat, or cold stress.

Drip Irrigation An irrigation system that allows passage of water through emitters placed right underneath the plant\’s root under slow pressure.

Evergreen Plants the remain green throughout the year.

Fertilizer Ratio A comparison of the amounts of nitrogen phosphorus, and potassium in the fertilizer. A 10-5-5 fertilizer has a 2:1:1 ratio or two parts of nitrogen to one part available phosphoric acid (P2O5) and one part soluble potash (K2O).

Foliar Burn Dehydration of leaf or stem tissue due to contact with a high concentration of fertilizer or pesticide.

Fungicide A chemical used to control a disease caused by a fungus.

Fungus A lower form of plant life that lacks chlorophyll and is therefore unable to produce its own food. Most turfgrass diseases are caused by fungi that feed on grass plants.

Germination The sprouting of a seed is the technical definition, but many turf managers use the term to mean the first visible appearance of a seedling when it emerges from the soil.

Herbicide A chemical used to control weeds, also called a weed killer.

Hydroseeding Mixing seed with water and spraying it on the planting site. The mixture may also contain fertilizer and mulch. This method of seeding is also referred to as hydraulic seeding.

IPM Integrated Pest Management is an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices. IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment. This information, in combination with available pest control methods, is used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment.

Lime Various calcium and magnesium compounds used to decrease soil acidity (raise soil pH).

Moss A low-growing, small primitive plants that may be found in shaded, wet, or poorly drained turf areas.

Overseeding Seeding into an existing turf.

Perennial A plant that has a life span of more than two years.

pH The measurement of the acidity or alkalinity of a soil. A pH of 7.0 is neutral; below 7.0 is acidic; above 7.0 is alkaline.

Postemergence Herbicide A chemical applied to control weeds after they have emerged from the soil.

Preemergence Herbicide A chemical applied to control weeds before their emergence from the soil.

Selective Herbicide A herbicide that kills one type of plant but does not seriously affect other types of plants.

Sod Pieces or strips of live grass, including leaves, crowns, stolons, rhizomes, roots, and adhering soil, which are used for vegetative planting.

Spot Treatment Treating a small area infested with a pest rather than applying the pesticide to the entire turf area.

Tensiometer An instrument that measures the tension at which water is held in the soil. Tensiometer readings can be used to determine irrigation needs.

Thatch The accumulation of undecomposed or partially decomposed organic material located above the soil surface. The thatch layer is primarily composed of dead and living root and stem tissue.

Topdressing Spreading a thin layer of soil mix over a turf area and working it into the turf to stimulate thatch decomposition and to smooth the surface.

Warm Season Turfgrass A turfgrass species that grows best when temperatures are in the 80 – 95 °F (27 – 35 °C) range.