Glossary of Lawn and Garden Terms
Absorption (plant) – The entrance or taking-in of a
chemical or nutrient into the plant.
Acid soil – Soil with pH less than 7.0. Raise soil pH
(lower acidity and raise alkalinity)
by adding lime.
Acre – A measure of land totaling 43,560 square feet. A
square acre is 208.75 feet on
Aerate – Loosen compacted soil to allow oxygen, water
and nutrients to get below the surface.
Aeration is best done by removing plugs of soil from the
lawn, rather than punching holes into the lawn.
Aerobic – The presence of air (oxygen) within an
environment, in contrast to anaerobic conditions
which is the absence of oxygen.
Alkaline soil – Soil having a pH more than 7.0. Lower
soil pH (raise acidity and lower alkalinity)
by adding sulfur.
Amendments – Organic substances added to the soil to
improve moisture retention, oxygen level
and nutritional content.
Amine – A phenoxy herbicide formulation that is less
prone to vaporizing and potentially moving
off-site than the ester form. Also see phenoxy herbicides,
Anaerobic – The absence of air (or free oxygen) within
an environment. See aerobic.
Analysis – Determination of (chemical) components by
percentage of total weight.
Annual – A plant that germinates, grows, produces
flowers and seeds, and dies within one
Annual, summer – A plant that begins growth in the
spring or early summer, thrives over summer,
flowers, produces seed and dies in the fall when the
first frost occurs
Annual, winter – A plant that begins growth in the late
fall and early spring, flowers,
produces seed and dies the following summer.
and located above the sheath.
Blend (seed) – A combination of two or more varieties
(cultivars) of a single turf grass species.
Broadcast application – Uniform distribution of a
pesticide or fertilizer (or seed mix or blend)
over an entire area through a rotary type spreader.
Broadleaf – A term applied to non grass-like plants
(dicots); often used in the context of weed control. Examples include dandelion
and white clover.
Broadleaf herbicide – A weed killer designed to
specifically kill broadleaf weeds without damaging
Bulb – An underground modified stem, usually covered by
a papery exterior. Bulbs are the growth
and food source for many flowering perennials.
Bunch-type growth – Plant development through the
formation of clusters of tillers (shoots) at
or near the soil surface. Rhizomes or stolons are absent.
to insure that it will accurately deliver the right amount
of material to the right amount of area.
Carbohydrate – Chemical compounds composed of carbon,
hydrogen, and oxygen. Examples
include starch, sugar, and cellulose.
Chlorophyll – The green pigment in leaves. When present
and healthy usually dominates all
Chlorosis – Absence of the green pigment chlorophyll
from plant leaves usually due to environmental
or genetic factors.
Clay – Very fine soil particles. Clay soils (soils
containing a high percentage of clay particles) are
often called heavy soils and are characterized by slow
movement of water through the soil.
Clay soils can be improved with soil amendments such as
manure, peat or mulch.
Clippings – Leaf blades and, in some cases, stems and
sheaths, cut off by mowing. Decompose readily
due to their relatively high water content and generally
simple chemical compounds.
Compaction (of soil) – Increase in soil density through
destruction of its pore space, as by excessive
traffic or working the soil; especially impenetrable when
Complete fertilizer – Any fertilizer product containing
at least nitrogen, phosphorus, and potassium.
Complete metamorphosis – An insect life cycle going
through the 4 distinct stages of egg, larva,
pupa and adult. The larva stages include several important
turf grass pests associated with caterpillars,
grubs and maggots.
Compost – Partially to completely decomposed organic
materials. It is typically made by piling a
mixture of grass clippings, leaves, etc., in a mound and,
periodically stirring and mixing the pile
hastening the decomposition process.
Contact herbicide – A weed killer that kills primarily
by contact with plant tissues.
Cool-season turf grass – Turf grass species whose
growth is favored during the cooler portions
(60° – 75°F) of the growing season (spring and fall); may
become dormant, injured or even
killed during hot, dry weather. Varieties include Kentucky
bluegrass, perennial ryegrass, annual
ryegrass, tall fescue and the fine fescues.
Core Aeration (soil) – The mechanical removal of soil
cores to improve soil air exchange,
water absorption and soil compaction. Cores are left on the
lawn where they break down and
help increase microbial decomposition of dead organic
Crown – A tightly compressed stem-like structure or
growing point that pushes new leaves
upward as they form and grow. In lawn grasses it is located
at the base of the plant at or near
the soil line. The location of the crown allows regular
mowing to be done while not compromising
the plants ability to re grow.
Cultivar – A group of cultivated plants distinguished
by various features such as color, growth habit or
leaf form that, when reproduced through seed or vegetative
means, retain their distinguishing features.
Cultivation – As applied to turf, cultivation means
working the soil and/or thatch without destroying
the entire lawn surface; examples of cultivation include
coring, slicing, spiking.
Cultural practices – Various horticultural methods and
techniques used to care for plants in the yard
and garden. Examples include watering, fertilizing, mowing,
weeding, and edging.
levels of damage occur. Used to determine when, if any,
pesticides are applied to control
a pest population.
Deciduous – A tree or shrub that loses all of its
leaves at once, usually in the fall.
Decomposition – The rotting or decaying of an organic
Disease – An interaction between a grass plant,
pathogen and its environment that impairs
the normal function or development of a plant.
Disease Die off – Die off of turf due to a fungi that
lawn is not able to overcome. Weather
conditions play a major roll causing this problem.
Dollar spot – Lawn disease that creates small patchy
spotting in which the grass dies off,
ranges in color from tan to straw.
Dormant – A condition of significantly reduced activity
where little if any growth occurs and
where rates of physiological activities, like
photosynthesis, are minimal or non-existent.
Drip Line – The circle which would exist if you drew a
line below the tips of the outer most
branches of a tree or plant.
Drought – Extended periods of dry weather often causing
moderate to severe stress in turf.
It can be particularly damaging when combined with high
Drought tolerance – The grass plant’s ability to
withstand extended periods of dry conditions
without incurring permanent damage. See also tolerance.
and their surrounding environment.
Endophyte – A plant living and functioning within
another plant. For example, a fungus. Turfgrass
cultivars are bred to include endophytes to discourage
damage from certain insects.
Environment – The sum of all the physical, chemical and
biological components to which
an organism is subjected. Soil, water, air, plants, animals,
and human beings comprise the
environment to which turf grass communities are subjected.
Eradicate – To completely eliminate something from an
area or the environment.
Erosion – The wearing away and transport of soil from
land areas by wind or running water.
Ester – A phenoxy herbicide formulation that is more
prone to vaporizing and potentially
moving off-site than the amine form. Also see phenoxy
Evaporation – Water loss back to the atmosphere through
the vaporization of water.
Evapotranspiration (ET) – The combination of
evaporation (water loss from land and water
surfaces) and transpiration (water loss from plants).
Evergreen – Plants that do not lose all of their leaves
at once. Evergreens can be conifers or
inorganic plant foods which may be either liquid or granular
used to amend the soil in order
to improve the quality or quantity of plant growth.
Fertilizer analysis – The amount of each nutrient
(N-P-K) in a fertilizer container expressed
as percent of the total weight.
Fertilizer burn (foliar burn) – Plant injury (and
usually death) caused by desiccation of tissue
due to contact with high concentrations of certain
Fibrous roots – Profusely branched roots consisting of
many lateral rootlets and usually no main or
Field capacity – The point at which soil becomes
saturated and cannot absorb any more water.
Foliar Feeding – Fertilizer applied in liquid form to
the plants foliage in a fine spray.
Fungicide – A pesticide used to destroy or suppress
Fungus – (pl. fungi) A non-vascular (i.e., plants that
do not contain water and nutrient
conducting vessels) plant that lacks chlorophyll. Some
examples are: mushrooms, molds,
rusts, and yeasts.
Granular – Pesticide or fertilizer formulations in
which the active ingredient or nutrient is
attached to small, dry particles of some inert carrier such
as clay or ground corn cobs.
Grass – A common name for members of the Grass
(Gramineae) family of plants.
Groundcover – A horticultural term applied to
low-growing vegetation covering the ground;
usually refers to broadleaf plants rather than lawn grasses.
Herbicide – A substance used to kill plants. A
herbicide can be selective (designed to kill a narrow
range of plants) or non-selective (designed to kill any
plant it contacts). Herbicides can also be
pre-emergent or post-emergent.
High-maintenance lawn – Lawn areas composed of turf
grass species and varieties requiring
higher levels of water, fertilizing and mowing to remain
Host plant – Any plant that provides nutrition (and
possibly shelter) for a plant pest to survive.
That is, any plant that an insect or pathogen lives on is a
Hybrid – A cross between two plants of different
variety, species or genus. Hybrids are usually
created to produce plants with specific characteristics,
such as disease resistance, unique flower
rates; sandy soils have high infiltration rates.
Inorganic (fertilizer) – Products used for supplying
nutrients to a lawn; generally composed of
simple, mostly water soluble nutrient salts that are
immediately available for plant use following
Insecticide – A specific category of pesticides used
for controlling insects.
Irrigation – The use of automated or manual systems for
applying supplemental water for the
benefit of growing plants and replenishing soil moisture.
manufacturer listing the contents, directions for use, and
precautions. A pesticide
label is considered a legal document that is approved and
registered by the U.S.
Environmental Protection Agency and the State Department of
Larva – The immature or worm stage (e.g., caterpillars,
maggots, and grubs) of
an insect that goes through 4 distinct lifecycle stages
(i.e., egg, larva, pupa, adult)
in its development. (See complete metamorphosis.)
Lawn – That portion of a yard or land area covered with
grass plants kept short through
Leaching – The downward movement in water of pesticides
and/or nutrients through the soil column.
Ligule – a membranous or hairy appendage between the
sheaf and blade of a grass leaf.
Lime – mineral that when applied, reduces acidic levels
of soil (increases soil pH); pH 6.5
level is perfect.
Liquid fertilization – A method of applying plant
nutrients as a solution of dissolved fertilizer salts.
Loam – A soil type composed of clay, silt and sand
particles in relatively equal amounts. Loam
is considered ideal for plants because it drains well but
does not dry out quickly.
Low toxicity – Term which the EPA uses for pesticides
that have very low toxic levels.
Low-maintenance lawn – Lawn areas composed of turf
grass species and varieties tolerant of
reduced levels of water, fertilizer and mowing while still
adult beetle or caterpillar into an adult butterfly.
Microbial – Effects associated with the action or
influence of microorganisms.
Micro-nutrient – A nutrient required by plants in small
or trace quantities. Does not
include the major plant nutrients (nitrogen, phosphorus and
Microorganisms – Living plants or animals (such as
bacteria, fungi, or protozoa) that are
so small they can be seen only with the aid of a microscope.
Minerals – The inorganic materials that make up a
portion of the soil derived from rocks;
they are usually of specific composition and crystalline in
Mowing – The periodic and usually regular cutting of a
lawn area to a specified height for its
intended use and function. Accomplished with mowers, either
manual or power operated.
Mulch – Non-living material used to cover the soil
surface for purposes of controlling weeds,
conserving moisture, reducing soil temperatures, and in some
instances, improving appearance.
Examples are wood chips, compost, and leaves.
Mulching mower – Mowers specifically designed to finely
chop grass clippings and forcibly direct them back into the lawn leaving a
clean, uniform appearance to the surface.
plant proteins. Adequate nitrogen produces good green color
and vigorous plants. Shortages
of nitrogen are usually indicated by yellowing leaves and
poor growth. Excess nitrogen can
result in unhealthy, lush growth making the plants more
vulnerable to environmental stresses
such as heat, drought, frost and, increased disease
Non-selective – A term applied to a category of
herbicides that does not discriminate in its
effect on one type of plant over another. For example, both
grasses and broadleaf plants would
be injured or killed as opposed to selectively killing
broadleaf plants without affecting the
grasses in a lawn area.
N-P-K – Chemical symbols for nitrogen (N), phosphorus
(P) and potassium (K). On a container
of fertilizer, these nutrients are always expressed as
percentages contained in the package and
are always shown in the order N-P-K.
Nutrient release rate – The speed at which plant
nutrients, especially N, become available for
plant use following application to a lawn. This rate is
often determined by the product, water
and temperature conditions at the time of application.
Nutrients (plant) – Mineral elements considered
essential for plant growth. There are presently
16 minerals known to play essential roles in plant
Nymph – The immature stage between the egg and adult of
some insect groups; nymphs look
like the mature adult in form but do not have fully
developed wings and are not able to reproduce.
carbonates. Often refers to any part of, or anything
produced by, plants or animals.
Organic matter (abbrev. OM) – Naturally occurring
material such as manure, sewage
sludge, peat, grass clippings, etc. Organic matter is often
used as a soil amendment.
Overseed or overseeding – The process of incorporating
seed into an existing lawn
area for the purpose of lawn repair or introduction of
different grass species.
Peat – A partly decomposed plant material found in
marshy areas. Identification or
origination of parent plant material may still be possible
(e.g., sphagnum peat moss).
Perennial – Plants that live two or more years
producing flowers and seeds in successive
Permanent wilting point – The point at which plant roots can
no longer extract water from
Pest (plant) – Any insect, mite, rodent, nematode,
fungus, weed, or other organism capable
of causing plant stress, injury or death through disease,
consumption of the plant or competition.
Pesticide – Any chemical (or mixture of chemicals) or
biological agent used to control plant or
animal pests in order to protect and/or preserve desirable
pH (soil) – A numerical measure of soil acidity or
alkalinity based on the hydrogen ion (H+)
concentration in the soil. A pH of 7 indicates neutral
conditions (neither acidic or alkaline);
above 7 is basic (alkaline), below 7 is acidic.
Phenoxy-type herbicides – A category of systemic weed
killers that have a chemical structure
composed of six carbon atoms joined together in a ring
formation. Two examples are 2,4-D
and mecoprop (MCPP).
Phosphorous – One of the major plant nutrients;
important in root growth and plant energy
functions. The middle number of a fertilizer analysis N-P-K.
Photosynthesis – The chemical plant process where
carbohydrates are formed by combining
carbon dioxide and water in the presence of light; occurs in
the chlorophyll containing parts of
the plant (i.e., leaves and stems).
Pore space – Spaces within soil that contain air and
water. Provides room for expansion of
fibrous roots. Sandy soils contain the most pore space: clay
soils contain the least pore space.
Post-emergence – Generally refers to the application of
an herbicide after the weed has emerged
(and is usually visible) from the soil.
Potassium – One of the major plant nutrients important
in maintaining general plant health and
vigor. Often associated with improved stress and disease
tolerance. It is the third number in the
fertilizer analysis N-P-K.
Pre-emergence – Generally refers to the application of
an herbicide before the weed emerges
from the soil. Target plants are most often not visible above
ground at the time of application.
as soon as water is applied and the fertilizer granule
dissolves. Can also be applied in liquid
formulations. Plant responds with quick green-up and rapid
rates of growth however, they
can result in lawn “burning” if they are over applied or if
applied during excessive heat
without being watered in.
Red thread – Lawn disease that causes blades to turn
tannish brown with thin thready
attachment at the tips of the grass blade.
Renovation, turf – Improving a stand of turf through
replanting into an existing lawn area.
May also include practices associated with rejuvenation.
Rhizomatous – A spreading growth habit resulting from
the production and elongation of rhizomes.
Rhizome – An elongated underground stem with scale-like
leaves and adventitious roots originating
from the nodes (bud containing areas along a stem).
Root – The fibrous, underground part of a plant
associated with mineral and water absorption.
Root zone – That portion of the soil column occupied by
are characterized by rapid water movement through the soil.
Sandy soils can be improved
with soil amendments such as manure, peat or mulch.
Scalping – An undesirable mowing practice that removes
an excessive amount of green
leaves and shoots at any one mowing. It can seriously weaken
or even kill the turf grass.
Selective – The term usually applied to an herbicide
that has the ability to only destroy one
type of plant while not affecting others. For example, a
post emergence, broadleaf herbicide
will kill broadleaf plants (such as dandelions) in the lawn
without affecting the grass plants.
Shade – An area of reduced light quantity (and often
quality) resulting from the partial or
complete obstruction of direct sunlight.
Sheath – The tube shaped, basal section of the grass
leaf enclosing the stem.
Shoot – Above ground, vertically oriented growth giving
rise to both leafy growth and
Shoot density – The number of shoots contained in a
specified area of lawn.
Silt – Soil particles that are larger than clay and
smaller than sand.
Slit-seeding – The use of a machine known as a
slit-seeder to seed a new lawn area or
overseed an existing area. Slit-seeders utilize a series of
vertically rotating blades to cut
small grooves into the soil for improved seed-to-soil
Slow-release nitrogen source – Nitrogen from these
sources becomes available as the
product is broken down by soil microbes and/or chemical
action. Plant responds with a
slightly slower rate of green-up and growth. Usually this is
a desirable characteristic.
Sod – Squares or strips (rolls) of turf grass cut from
a production field and usually with a
thin layer of soil still attached that is used for
vegetatively installing a turf grass area.
Soil – The earth’s thin upper layer capable of
supporting plant growth. It is characterized
by such things as texture, structure, color, and fertility
which distinguish it from material
like gravel, sand or bedrock that also cover a portion of
the earth’s surface.
Soil structure – The combining of microscopic soil
particles through the action of soil
microbes into larger units commonly known as soil granules,
crumbs or aggregates.
Loose, crumbly soil structure is a must to sustain health
Soil test – A scientific analysis of a soil sample that
determines its pH, texture, organic
matter content and various degrees of chemical composition.
They are used to assess a
soil’s suitability for particular uses and any necessary
modifications to prepare it for the
Soluble (fertilizer) – Fertilizers that are made up of
easily dissolved components in water
which are immediately available for plant use; they can
result in lawn “burning” more
easily that slow-release fertilizers. (See quick-release
Spot treatment – Generally refers to the application of
a pesticide to a limited or small area.
In the case of herbicides, it may also be applied to the
treating of individual plants or infested areas.
Stem – The horizontal or vertical axis of a plant
supporting leaves, buds and flowers.
Stolon – An elongated stem growing along the ground
surface and giving rise to leaves and
adventitious roots at the nodes (bud containing areas along
Stoloniferous: – spreading growth habit resulting from
the production and elongation of stolons.
Stress (plant) – Usually applied to environmental
factors restricting normal or healthy plant
growth. Some of these factors are heat, drought, compacted
soils, traffic, water logging and cold.
Summer Patch – Lawn disease that appears as green
growth in the middle of dead brown patches
or partially decomposed, that accumulates between the green
vegetation and soil surface.
Tiller – A lateral shoot, usually erect, that develops
from axillary buds in the crown.
Tolerance – The plant’s ability to withstand stresses
associated with unfavorable environmental
conditions or the application of pesticides.
Topsoil – The upper portion of soil that is generally
higher in organic matter in comparison to the
subsoil and usually has more favorable characteristics of
soil fertility, aeration and structure.
It is also described as a synthetic organic fertilizer as it
contains the element carbon in
its chemical structure.
rate and amount that a turf grass species or cultivar is
able to grow and spread.
warmer periods (80° – 95° F) of the growing season.
Varieties include Bermuda grass,
Zoysia grass, St. Augustine grass grown in the Southern
Watering-in – Water applied to turf immediately after
the application of some pesticides
or fertilizers to dissolve and/or move materials into the
Weed – An undesired, uncultivated plant growing in a
manner so as to adversely compete
with desirable plants for water, light and nutrients, or
destroy aesthetic qualities of a lawn.
Winterizer – specially combined fertilizer to give turf
proper nutrients before going dormant
for the winter.