Select the first letter of the word from the list above to jump to appropriate section of the glossary. If the term you are looking for starts with a digit or symbol, choose the '#' link.

ACID

a sour substance: An acidic solution has a pH below 7

 

AERATION

Supplying soil and roots with air or oxygen.

 

ALKALINE

refers to medium or nutrient solution with a high pH: Any pH over 7 is considered alkaline

 

AMPERE (AMP)

the unit used to measure the strength of an electric current: A 20-amp circuit is overloaded when drawing more that 17 amps

BLOSSOM BOOSTER

fertilizer high in phosphorus (P) that increases flower yield

 

BOLT

term used to describe a plant that has run into seed prematurely

 

BURN

Leaf tips that turn dark from excess fertilizer and salt burn

CARBON DIOXIDE (CO2)

a colourless, odourless, tasteless gas in the air necessary for plant life. Occurs naturally in the atmosphere at .03%

 

CHLOROSIS

the condition of a sick plant with yellowing leaves due to inadequate formation of chlorophyll: Chlorosis is caused by a nutrient deficiency, usually iron or imbalanced pH.

 

CLONE

A plant produced through asexual reproduction including, but not limited to, cuttings, layering and tissue culture

 

CONDITIONING

to soak new Rockwool in an acidic solution to lower the pH from 8,0 to 5.5

DAMPING OFF FUNGUS

disease that attacks young seedlings and cuttings causing stem to rot at base: Overwatering is the main cause of damping-off

 

DISSOLVED SOLIDS

the amount of dissolved solids, usually fertilizer salts, that are measured in water in parts per million

 

DRIP SYSTEM

a very efficient watering system that employs a main hose with small water emitters. Water is metered out of the emitters, one drop at a time

ELECTRICAL CONDUCTIVITY (EC)

the ability of a solution to carry electrical energy as a result of the elements and compounds in the solution

FOLIAR FEEDING

misting fertilizer solution which is absorbed by the foliage

 

FUNGICIDE

a product that destroys or inhibits fungus

 

FUNGUS: DAMPING OFF FUNGUS

disease that attacks young seedlings and cuttings causing stem to rot at base: Overwatering is the main cause of damping-off

GERMINATION

the process of causing the initiation and development of a plant from seed

HALOGEN

any of the elements flowering, chlorine, bromine, iodine and astatine existing in a free state: Halogens are in the arc tube of a halide lamp

 

HARDEN-OFF

to gradually acclimatize a plant to a more harsh environment. A seedling must be hardened-off before planting outdoors

 

HID

High Intensity Discharge (referring to light bulbs used in hydroponic gardens)

 

HOOD

reflective cover of a HID lamp: A large, white Hood is very reflective

 

HOR

the abbreviation stamped on some HID bulbs meaning they may be burned in a horizontal position

 

HORMONE

Chemical substance that controls the growth and development of a plant. Root-inducing hormones help cuttings root

 

HYBRID

an offspring from two plants of different breeds, variety or genetic make-up

 

HYDRATED LIME

instantly soluble lime, used to raise or lower pH

 

HYGROMETER

instrument for measuring relative humidity in the atmosphere: A hygrometer will save time, frustration and money

INTENSITY

the magnitude of light energy per unit: Intensity diminishes the farther away from the source

KILOWATT-HOUR

measure of electricity used per hour: A 1000 watt HID uses one kilowatt per hour

 

LEAF CURL

leaf malformation due to overwatering, over fertilization, lack of magnesium, insect or fungus damage or negative tropism

 

LUMEN

measurement of light output: One lumen is equal to the amount of light emitted by one candle that falls on one square foot of surface located one foot away from one candle.

 

MACRO-NUTRIENT

one or all of the primary nutrients N-P-K or the secondary nutrients magnesium and calcium

 

MICRO-NUTRIENT

also referred to a TRACE ELEMENTS ,including S, Fe, Mn B, Mb, An and Cu

 

MONOCHROMATIC

producing only one colour: LP sodium lamps are monochromatic

NFT (NUTRIENT FILM TECHNIQUE)

nutrient is fed into growtubes where the roots draw it up. A thin film of nutrient allows the roots to have constant contact with the nutrient and the air layer above at the same time.

 

NUTRIENT

plant food, essential elements N-P-K, secondary and trace elements fundamental to plant life

 

NUTRIENTS, SECONDARY

Calcium (Ca) and magnesium (Mg)

pH

a scale from 1 to 14 that measures the acid to alkaline balance of a growing medium (or anything): In general plants grow best in a range of 6 to 6.8 pH 6.3 is considered ideal. If the pH is not within the acceptable range nutrients may not be absorbed to maximum capacity

 

PERLITE

1. Sand or volcanic glass, expanded by heat, holds water and nutrients on its many irregular surfaces
2. Mineral soil amendment

 

PHOTOPERIOD

the relationship between the length of light and dark in a 24 hour period

 

PHOTOSYNTHESIS

the process by which plants use light energy to collect carbon dioxide from the atmosphere and convert it to chemical energy in the form of sugar

 

POLLINATION

the transfer of pollen from a stamen to a pistel. Often enhanced by environmental manipulation , plant movement through shaking or vibrating or the introduction of bees into the growing area

 

PROPAGATE

1 Sexual - produce a seed by breeding different male and female flowers
2 Asexual - to produce a plant by taking cuttings

 

PYRETHRUM

natural insecticide made from the blossoms of various chrysanthemums

RESERVOIR

any container of a variety of constructions which holds water in reserve for use

 

REVERSE OSMOSIS (R/O)

water that has had all contaminates and salts removed.

 

ROCKWOOL

inert, soilless growing medium consisting of thin strand-like fibres made from rocks

 

 

SECONDARY NUTRIENTS

Calcium (Ca) and magnesium (Mg)

 

SYSTEMIC

used in reference to a disease within the plant tissue, not initiated from the external cells. Also refers to materials and compounds which are taken up or absorbed by the plant and designed to fight disease

 

 

VERMICULITE

mica processed and expanded by heat. Vermiculite is a good soil amendment and medium for rooting cuttings

 

WETTING AGENT

compound the reduces the droplet size and lowers the surface tension of the water, making it wetter. Liquid concentrate dish soap is a good wetting agent if it is biodegradable

 

WICK

part of a passive hydroponic system using a wick suspended in the nutrient solution, the nutrients pass up the wick and are absorbed by the medium and roots