Hardening off—The process of slowly changing a plant’s light, temperature, water, or fertilization to prepare it for a change in weather or location.
Herbaceous—With the texture of a herb as opposed to a woody texture.
Herbicide—A chemical applied to the soil to control weeds. Selective herbicides kill only specific plants while leaving surrounding vegetation unharmed; nonselective herbicides kill all vegetation in the area to which they are applied.
Humus—The last stages of decomposition of animal or vegetable matter into a soft brown or black substance.
Hybrid—A plant resulting from the cross of two species.