LACEWING: A beneficial insect. About one inch in length will eat mites, aphids, and thrip (see our section on insects).

LANDSCAPE ARCHITECT: A professional licensed by the state and know the proper processes of landscape design, construction, grading, drainage.

LANDSCAPE FABRIC: Probably one of your best solutions against weeds for beds. This can be a variety of materials: newspaper, plastic, porous fibers, burlap. It provides a barrier for weeds to germinate. This is then dressed with mulch of any kind.

LATEX: Milky sap which exudes from cut surfaces of a few house plants.

LATH: An overhead structure of evenly spaced slats of wood or other materials used to create shade.

LAYERING: a method of propagation in which adventitious roots form before the new plant is severed from the parent plant.

LEACHING: The removal or loss of excess salts or nutrients from soil. The soil around over fertilized plants can be leached clean by large quantities of fresh water used to 'wash' the soil. Areas of extremely high rainfall sometimes lose the nutrients from the soil by natural leaching.

LEADER: The main or terminal shoot of a tree.

LEAF CUTTING: A method of propagation. A leaf is removed and is placed in vermiculite or perlite for future baby plants.

LEAF MOULD: Partially decayed leaves used in some potting mixtures. It must be sieved and sterilized before use.

LEAFLET: A leaf-like section of a compound leaf.

LEAF ROLLER: Different moths that will roll leaves when larvae.

LEGGY: Abnormally tall and spindly growth.

LEGUME: A plant whose roots form an association with soilborne bacteria that can capture atmospheric nitrogen. Some good examples of this association are peas and soybeans. See Inoculation.

LIMBING UP: Pruning off the lower limbs of trees, usually for ease of walking underneath or admitting sunlight.

LITHOPHYTE: Plants that grow on rocks or other areas that do not need soil. They will receive their nourishment from the air.

LOAM: Good quality soil. Adequate supplies of clay, sand and fiber must be present. Sometimes refered to as "top soil".

LONG DAY PLANT: a plant that requires a night shorter than its critical dark period, usually 12 hours or less, to develop flowers.