Horticulture Principles and Practices

Floriculture The science and practice of cultivating
and arranging ornamental flowering plants.
Flower stalk The stem of the plant that supports the
flower.
Foliar application A method of supplying nutrients to
plants by spraying the leaves with liquid fertilizer.
Forcing A cultural practice of manipulating plants to
flower at times other than their normal growing
season.
Form The overall shape of a plant.
Form flower A type of flower with a unique shape
such as bird-of-paradise, potea, or orchid.
Formal flower bed A symmetrically designed bed for
annual and perennial flowers.
Foundation planting Planting shrubs or ground
covers at the base of a house.
Foundation seed Seed stocks increased from breeder
seed.
Freestanding bed A bed designed to be accessible
from all sides.
Frost hardy Plants that are able to withstand frost.
Frost pocket A low-lying area more susceptible to
frost than the surrounding vicinity.
Frost tender Plants that are killed at temperatures
below freezing.
Fruit A mature, swollen ovary.
Fumigation Control of insects, disease-causing
organisms, weeds or nematodes by gases applied in
an enclosed area such as a greenhouse.
Fungicide A chemical used to control a fungus.
Furrow irrigation A method of irrigation by which
the water is applied to row crops in ditches.
G
Gall An abnormal swelling on a plant part.
Genetic engineering The manipulation of the genome
of an organism by incorporating genes from an alien
source.
Genotype The genetic makeup of an individual.
Germination (seed) Sequence of events in a viable
seed starting with imbibition of water that leads to
growth of the embryo and development of a
seedling.
Germination rate The percentage of seeds that will
germinate under favorable conditions.
Germplasm The protoplasm of the sexual
reproductive cells containing the units of heredity.
Gibberellin A plant hormone that stimulates growth in
stem and leaf by cell elongation and also influences
vernalization.
Glazing The clear or translucent material used to
cover a greenhouse or related plant growing
structure.
Grafting The method of asexual propagation in which
a branch or bud from one plant is implanted on
another.
Grain (caryopsis) A simple, dry, indehiscent fruit
with ovary walls fused to the seed.
Gravitational water The water that the soil is unable
to hold against the force of gravity.
Green manure crop A fast-growing plant grown for the
purpose of turning under the soil before it reaches
maturity to provide organic matter in the soil.
Greenhouse effect The heating of the air in an
enclosed translucent or transparent structure due to
trapped energy from the sun.
Ground cover Low-growing and spreading plants that
form matlike growth over an area.
Growing medium A material used for rooting and
growing plants.
Growth An irreversible increase in cell size and/or cell
number.
Growth regulator A synthetic or natural compound
that in low concentrations controls growth responses
in plants.
Guard cells Specialized epidermal cells that contain
chloroplasts and surround a stoma.
Guttation Exudation of water in liquid form from
plants.
Gymnosperm A seed plant with seeds not enclosed by
a megasporophyll or pistil.
Gynoceium The female part of a flower or pistil
formed by one or more carpels and composed of the
stigma, style, and ovary.
H
Haploid Having only one complete set of
chromosomes.
Hardening off The cultural practice preceding
transplanting whereby plants are acclimatized to
field growing conditions by gradually subjecting
them to decreasing temperature, moisture, and
nutrition.
Hardpan A layer of compacted soil that slows or stops
the movement of water.
Hardwood cutting A cutting made from the mature
growth of a woody plant, usually taken in late fall or
early spring.
Hardy plant A plant adapted to adverse climatic
conditions, such as cold temperature, prevailing in
the growing area.
Heading back A pruning strategy used to control the
size and shape of shrubs by cutting back shoots to
the parent branch to encourage new growth.
Heaving The partial lifting of plants out of the ground,
frequently breaking their roots, as a result of
freezing and thawing of the surface soil during the
winter.
Heeling in A method of temporary storage of barerooted
trees and shrub seedlings before transplanting
by covering the roots with soil or some organic
matter in a shallow trench.
Glossary 749