F1 HYBRID: A first generation offspring of two purebred strains. An Fl hybrid is generally more vigorous than an ordinary hybrid.
F2 HYBRID: This is the product of two F1 plants that have been crossed. This is considered the second generation. This will not necessarily produce a great plant.
FAIRY RING: A circle of fungal growth.
FAMILY: One genus or several genera which have a basically similar floral pattern make up a family.
FASCIATION: This effects many herbaceous and woody plants. This is a genetic mutation or imbalance in growth caused by absorption of a herbicide.
FERTILIZE: The application of nutrients for plant growth.
FIBROUS-ROOTED: A root system which contains many thin roots rather than a single tap root.
FIELD GROWN: Grown in the field, as opposed to root cuttings which are grown in pots in greenhouses.
FLAT: A shallow box or tray used to start cuttings or seedlings.
FLORE PLENO: A botanical term describing a flower with extra petals.
FLORET: A small flower which is part of a much larger compound flower head.
FLOWER SPIKE: A flower head made up of a central stem with the flowers growing directly on it.
FOLIAR FERTILIZER: A fertilizer applied in liquid form to a plant's foliage in a fine spray so that the plant can absorb the nutrients through its leaves.
FORCE: manipulation of environmental factors to make a plant blossom out of season.
FORCING: The process of hastening a plants growth to maturity or bloom.
FOUNDATION PLANTING: Any plant that is used around a building for the sole purpose of making it look more esthetic.
FROND: A leaf of a fern or palm.
FROST: The condensation and freezing of moisture in the air. Tender plants will suffer extensive damage or die when exposed to frost.
FROST DATE: Frost dates are important to know for your gardening zone or planting area. This is the average expected last frost date for your area.
FROST HARDY: Plants that are able to survive winter frosts without damage to their leaves (i.e. evergreens) or damage to dormant stems, buts or roots (i.e. deciduous plants). Very much relative to geographic areas.
FROST TENDER: These plants will be damaged or killed by even the lightest of winter frosts.
FRUIT FLY: A small insect pest that will lay its eggs beneath the surface of developing fruits. The larvae will then grow quickly and exit through holes in the fruit or vegetable causing rot.
FULL SHADE: This shade is sometimes called deep shade and is created by mature trees.
FULL SUN: Six hours or more in the direct sun daily during the growing season of the year.
FROST FREE DATE: The approximate date of the last killing frost of spring.
FUNGICIDE: A chemical used to control mould caused by fungi.
FUNGUS: A primitive form of plant life which is known to the house plant grower as the most common cause of infectious disease - powdery mildew, sooty mould and area diseases caused by fungi.
FURROW: A depression in the planting garden either dug by a spade or a plow.
FUSARIUM: This fungal disease is soil borne and causes wilting and death mostly in herbaceous plants.