Plant Science Terms - N
N - see Nitrogen
N-P-K - acronym for the three major plant nutrients contained in manure, compost, and fertilizers. N stand for nitrogen, P for phosphorus, and K for potassium. It is also a ratio of Nitrogen to Phosphorous to Potassium in a fertilizer. These are the main nutrients required by plants
Nativar - plant that is a cultivar of a native plant
Native plant - plant indigenous to a specific habitat or area
Naturalize - design a garden with the aim of creating a natural scene. Planting generally is done randomly, and space is left for plants to spread at will; process whereby plants spread and fill in naturally
Necrosis (necrotic) - death of cells resulting in necrotic or dead plant tissue
Nectaries - cells of the petal of a flower that secrete nectar
Needs Good Drainage - plants that do not do well if they remain wet for extended periods of time and should be planted in locations or containers where water quickly drains
Nematicide - material that kills or protects against nematodes
Nematode - microscopic roundworms that live in soil and living tissue, as well as water, and survive as eggs or cysts
Netted veins - having branched veins that form a network, as the leaves of most dicotyledonous plants
Nitrate - plant-available form of nitrogen contained in many fertilizers and generated in the soil by the breakdown of organic matter. Excess nitrate in soil can leach to groundwater. (See also Nitrogen cycle)
Nitrifier - microbe that converts ammonium to nitrate
Nitrogen - primary plant nutrient, especially important for foliage and stem growth
Nitrogen cycle - sequence of biochemical changes undergone by nitrogen as it moves from living organisms, to decomposing organic matter, to inorganic forms, and back to living organisms
Nitrogen fixation - conversion of atmospheric nitrogen into plant-available forms by rhizobia bacteria living on the roots of legumes
Nitrogen, quick release - readily available sources of nitrogen that exhibit fast turf greening, short residual, and high burn potential, such as ammonium nitrate
Nitrogen, slow release - slowly available sources of nitrogen that exhibit slow turf green-up, long residual, and low burn potential, such as IBDU, urea formaldehyde
Nocturnal - active at night
Node - segment of the stem that bears a leaf, lateral bud, or a branch. A joint where leaves, roots, branches, or stems arise
Nomenclature - assigning of names in the classification of plants
Nonpoint source - relatively small, nonspecific source of pollutants that, when added to other sources, may pose a significant threat to the environment. (See also Point source)
Nonselective pesticide - pesticide that kills most plants or animals
Nonviable - not alive; nonviable seeds may look normal but will not grow
Normal - Water when the top of the soil in a pot is dry to the touch. For in ground plantings they will need some supplemental water if there is an extended dry spell but will not need constant watering
Normal to Wet - plants that need water when the top of the soil in a pot is dry to the touch but err on the side of wet rather than dry. These plants prefer that the soil be constantly moist and will not tolerate dry soils well and perform well when planted at pond edges
Noxious weed - weeds that have been declared by law to be a species having the potential to cause injury to public health, crops, livestock, land, or other property; very invasive, difficult to control plant
Nucleus - organelle within a cell that contains chromosomes and thus controls various cellular processes, including division into new cells
Nursery grower - person who produces or distributes ornamental plants
Nut - an indehiscent dry fruit similar to the achene except that the fruit wall is hard throughout. Offsets. Miniature bulbs grown to full size
Nutrient - any substance, especially in the soil, that is essential for and promotes plant growth. (See also Macronutrient, Micronutrient)
Nymph - immature form of those insects that do not pass through a pupal stage. Nymphs usually resemble the adults, but are smaller, lack fully developed wings, and are sexually immature but eat the same food, and reside in the same environment