OPEN GROUND: Ground for cultivation not protected by a covered structure.
ORGANIC: Literally, an organic compound is one containing carbon. Many organic compounds are produced from the breaking down of plant or animal remains, especially substances in rotting manure, compost and the like which in turn become plant foods. See inorganic.
ORNAMENTAL: A plant grown mainly for decorative effect.
OVARY: The part of the female organ of the flower containing the ovules.
OVULES: Female cells contained in the ovary of a flower.