A solution or medium that is chemically non-reactive.
The dissolving or washing out of soluble salts from a grow medium or soil.
Malformation of a leaf due to under- or over-fertilization, over-watering or damage caused by insects or disease.
A naturally-occurring mined mineral complex which will raise pH.
A chemically-sensitive paper that can be used to determine pH.
A unit of measurement of light that is used to rate the amount of output based on electrical wattage and other factors.
Classification for the major nutrients required for plant growth: Nitrogen (N), Phosphorus (P), and Potassium (K). Some systems include the secondary nutrients as macronutrients: Calcium (Ca), Magnesium (Mg) and Sulfur (S).
Classification for the minor nutrients required for plant growth, also known as trace elements: Iron (Fe), Boron (B), Copper (Cu), Molybdenum (Mb), Zinc (Zn), Manganese (Mn), Nickel (Ni), Cobalt (Co). Chlorine (Cl) and Sodium (Na) are sometimes included in this classification.
A device that measures the amount of moisture in a grow medium or soil.
Colonies of beneficial fungi which live on plant roots in a symbiotic association where fungireceive carbohydrates while plant roots receive enhanced mineral absorption capability.
0.000000001 of a meter. Used as a scale to measure wavelength in the electromagnetic spectrum, which includes visible light.
In this method of hydroponics, a thin film of nutrient solution is constantly flowing across the plant roots in a tray or trough. Like aeroponics, this system utilizes very little to zero growing media for plant roots to colonize which in the event of pump failure gives very little time before roots dry out and can lead to loss of crop. The advantage of a NFT system is the high level of oxygen in the root zone and the relative simplicity of the components using for fertigation. This system is most popular for growing leafy greens and herbs at the commercial production level.
A mineral that a plant can uptake and assimilate into its tissue; a plant food.
Leaf scorch that occurs from over-fertilization or application of excess salts, like nitrogen.
Carbon-based material, or a substance found in nature which is not processed.
used in gardening as a soil additive, peat moss is harvested from arctic bogs which take centuries to form.
A difficult aspect of growing plants is how to deal with harmful insects and diseases. Pest problems can be dealt with by using clean plant stock, minimization of exposure to outside environments and monitoring consistently. If insects do make it into your environment, using beneficial insects to combat the harmful ones or spraying with a variety of products that are targeted is the last resort. Preventing disease is not always possible, but using clean plant stock, keeping the environment clean, and preventing environmental conditions that favor the disease are the best steps to take.
A measure of the molecular concentration of hydrogen ions in a solution in a scale ranging from 1-14 with neutral being 7. Keep in mind that the pH scale is algorithmic-a reading of 6 is 10 times more alkaline than a reading of 5-so make changes very slowly. From 5.5-6.2 is considered an ideal range for hydroponics, depending on the grow medium or hydro method being used.
An electronic device that measures pH.
The amount of light received by plants during a 24-hour period.
The conversion of light energy to chemical energy (carbohydrates) by plants, which usually occurs in their leaves.
Growing plants by germinating their seeds or rooting cuttings from them.
Altering a plant into a desired form by cutting its leaves, stems, shoots, flowers or fruits.
A hydro system which circulates or “feeds” nutrient solution from a reservoir over and over again, until the reservoir is either “topped off” with additional nutrients or drained out completely and replenished. Ebb & flow (flood & drain) is the most common recirculating system in hydro, although NFT (nutrient film technique) and drip systems can also recirculate nutrient solution.
The exchange of gases by living organisms to support life; in the case of plants, consuming carbon dioxide and expelling oxygen as waste.
The area directly surrounding the roots of a plant.
A grow medium made from molten rock or inert material “spun” at high temperatures into a fibrous mass.
When a plant’s roots have grown to reach the limits of its container. Some plants prefer this, most should be transplanted.
Characterized by an accumulation of white, off-white or brown sediment on the surface of a grow medium or soil, and sometimes at the base of drainage holes on potted plants. Salt buildup reduces the amount of water molecules available for plant uptake.
A colloquial term meaning plant nutrients. A salt is actually an ionic compound with a cation from a base and an anion from an acid. Too many salts in a grow medium can cause plants to burn.
Able to be dissolved in water.
A complex carbohydrate that’s manufactured and stored by plants.
Tiny openings in the leaves of plants though which they take up nutrients, release water and take in CO2 (carbon dioxide.)
Simple carbohydrates manufactured by plants via photosynthesis. Sugars can also be added as supplements.
Refers to something that is transported throughout the plant.
The main vertical root of a plant; lateral roots run out from the tap root.
The temperature of a growing environment is crucial to maintain optimal growth and maximize the genetic potential of the plant. The ideal temperature will vary given the stage of growth and the type of plant being grown. During vegetative growth, plants are growing very rapidly and can tolerate higher temperatures than during fruiting and flowering. A typical safe range for vegetative plants is 75-80°F during the light (day) period and 55-60°F during the dark (night) period. For fruiting and flowering growth, the temperature range is 70-75°F during the day and 50-60°F during the night period. Monitoring the growing environment with a thermometer that has minimum and maximum temperature logging is a valuable tool to keep track of the fluctuation of temperature throughout the course of the day.
A large class of plant secondary metabolites that play a role in floral aroma and other plant processes, and are increasingly being studied for their medicinal qualities.
To prune or remove parts of plants to allow remaining plant, flowers or fruits to develop more fully.
To apply fertilizer or compost to the top of soil or grow media.
Glossary
Learn common hydroponic terms and concepts