Backcross (BX)A hybrid plant that has been bred with one of its parents (or a plant that is genetically similar) in order to create offspring that is closer to that of the original parent. This is often done to maintain rarer strains or strengthen those with desired recessive genes.

CannabinoidsThe chemical compounds unique to cannabis that act upon the human body’s cannabinoid receptors, producing various effects including pain relief and other medically beneficial uses. Marijuana’s most well-known cannabanoid is tetrahydrocannabinol (THC) due to the fact that it is the most abundant, and also because it produces the psychoactive effects (or the “high”) that drives the plant’s recreational use. However, there are over 113 known cannabinoids all with varying effects, so THC isn’t the only one.

CannabisA genus of a flowering plant in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized, Cannabis sativa, Cannabis indica and Cannabis ruderalis; C. ruderalis may be included within C. sativa; or all three may be treated as subspecies of a single species, C. sativa. The main active ingredient in cannabis is called tetrahydro-cannabinol, commonly known as THC, the ingredient in the plant that gives the “high.”

CBD – The abbreviation for cannabidiol. CBD is widely used as a medical treatment as research has shown it effectively treats pain, inflammation, and anxiety without the psychoactive effects (the “high” or “stoned” feeling) associated with THC. High CBD strains, such as Harlequin, are being bred more actively and appearing more frequently on the market.

Ceramic –  Ceramic Metal Halide (CMH) lamps are a variation of the traditional Metal Halide HID lamp. The Ceramic tube and the metallic atoms within it create a bluish light that is close to daylight with a CRI (color rendering index) of up to 96.

ConcentratesA potent consolidation of cannabinoids that are made by dissolving marijuana in its plant form into a solvent. The resulting products range from thick sticky oils (BHO) to moldable goo (budder/wax) to resinous bits (shatter). The classification of concentrates is often dependent on the manufacturing method and the consistency of the final product.

CloneRefers to a cutting from a cannabis plant, which can then be rooted and grown through a cloning process of the mother plant, from which the clone was cut.

Coco (Also Coco Coir) is a growing medium made of fibrous coconut husks. Coco gives the experience of growing in soil but with many of the benefits of growing in hydro (such as faster growth and bigger harvests.

Cross(referring to crossbreeding) is the result when two different plant strains are bred together.

Drain to waste  – Term referring to water runoff  drained into the ground and/or routed to a holding reservoir and then disposed of.

Ebb and Flow  – Also known as flood and drain or sometimes just as a flood table, ebb and flow is simply a method to flood your pots with a nutrient solution at regular intervals and then let it drain back into the reservoir.

E.C. – Electric Conductivity (EC) is the first step in determining the Total Dissolved Solids (TDS) measurement of the nutrient concentration of a hydroponic solution. A meter that measures the EC of a solution is then converted to PPM, (parts per million) to give you the TDS measurement.

Feminized  – Refers to seeds that have been selectively bred to produce only female plants. Feminized seeds are intended to make things easier for growers by eliminating the need to determine the sex of growing plants and remove males early on to prevent fertilization.

FIM – A plant training techniques that involve “pinching” or cutting off some of the newest growth (but not between nodes), designed to make better use of the available light, create more colas, and achieve bigger yields. FIM actually stands for “Fuck I Missed”, from the original developer of the technique. (SEE also Topping)

Fluorescent – A type of lighting which uses a low pressure mercury-vapor gas-discharge to produce light. An electric current excites the mercury vapor which causes a phosphor coating on the inside of the lamp to glow

HempA fibrous product produced from the male cannabis plant and used in the manufacture of rope, paper, beauty products, and a vast array of other products.

HID – High Intensity Discharge (HID) lamps are a type of electrical gas-discharge which include tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. The tube is filled with both gas and metal salts.

HPS – High Pressure Sodium (HPS) lamps work by creating an electric arc through vaporized sodium metal.

HybridA plant that is genetically a cross between two strains of cannabis. Hybrids can happen unintentionally, but they are usually bred specifically to combine desired traits of the original plants. Most marijuana on the market today are some form of hybrid.

HydroponicsA system of gardening that does not use soil. Plants are grown in water and receive their nutrients from the addition of solutions rather than soil.

Incandescent – A traditional type of electric light with a wire filament heated to such a high temperature that it glows with visible light (incandescence).

Indica –  A species of the cannabis family. Indica strains tend to be shorter and bushy with leaves that are fat and dark green colored due to the higher amount of chlorophyll and a shorter flowering period than sativas. The Indica high is often related to being Relaxing & Laid back, Relieves pain and aches, Reduces anxiety & stress, Aids sleep, Reduces inflammation, Helps relieve spasms and seizures and Stimulates the appetite. (SEE also “Did We Get it Wrong”)

Induction Fluorescent – Based upon a conventional fluorescent lamp bulb in which current is induced by an external coil of wire via electrodynamic induction instead of internal electrodes.

Induction Sulfur Plasma – Uses electrostatic induction to energize a bulb filled with sulfur vapor or metal halides.

KiefA collected amount of trichomes that have been separated from the rest of the marijuana flower. Since trichomes are the sticky crystals that contain the vast majority of the plant’s cannabinoids, kief is known to be extremely potent.

LST – Low Stress Training (LST) is a cannabis plant training technique to gently bend plants as they grow. This naturally creates multiple bud sites to produce higher yields.

LandraceA landrace refers to a local variety of cannabis that has adapted to the environment of its geographic location. Landrace strains are oftentimes named after their native region, like Afghani, Thai, and Hawaiian, and traces of landraces are sometimes detectable in the names of their crossbred.

LED -Light Emitting Diodes is a two-lead semiconductor light source. Electrons recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence

Metal HalideProduces light by an electric arc through a gaseous mixture of vaporized mercury and metal halides, (compounds of metals with bromine or iodine). It is a type of high-intensity discharge (HID) gas discharge lamp.

PARPhotosynethically Active Radiation (PAR) meters measure light intensity within the spectrum that plants use most to photosynthesize (excluding UV light) from 400 to 700 nanometers, which covers both the blue and red spectra of light. A PAR meter will measure the density of your light coverage.

PH – (potential of hydrogen) is a numeric scale used to specify the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH 7, being neither an acid nor a base.

PhenotypeThe general physical characteristics of the plant such as height, color, branching, leaf configuration down to cell structure and additional markers that can be used to identify the plant genetics.

Photoperiod – The daily number of hours of day (light) vs. night (dark). In nature, long nights signal the plant that winter is coming and that it is time to flowers and produce seeds. As long as the day-length is long, the plants continue vegetative growth.

PPM  – Parts per million (ppm) is used to measure chemical concentration, usually in a solution of water. SEE also EC and TDS

PistilThe part of a female plant’s anatomy. On cannabis, it’s identified as the little hair-like extensions on the flowers that range in color from white to red to darker orange-brown. When plants are going to be fertilized, the pistil acts to collect the male pollen.

Recirc (Short for Recirculating) is when the runoff from the nutrient solution is collected, replenished and reapplied to the medium.

RO Water – Reverse Osmosis, (RO), is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from water.

Ruderalis A species of the cannabis family. Ruderalis is a short and stalky plant, especially when compared to its Sativa and Indica counterparts. What really sets ruderalis apart is its flowering cycle that is induced according to its maturity instead of being activated by the photoperiod like indica and sativa varieties. Modern ruderalis hybrids usually begin to flower between 21 and 30 days after the seeds have been planted, regardless of the light cycle. This is why most ruderalis hybrids are attributed as “autoflowering” strains. The effects of cannabis ruderalis alone are minimized by its naturally low concentrations of THC. (SEE also “Did We Get it Wrong”)

Runoff  –  Is the water, as well as the substances carried in it, drained away. Runoff can provide an indication of how your water, fertilizer, and grow medium are interacting chemically.

Sativa –  A species of the cannabis family. Sativa strains tend to grow tall, be long and thin, and have a longer to flowering period. The Sativa high is often related to being Energizing, Uplifting, Stimulates creativity and thoughts, Promotes sense of well-being, Relieves headaches and migraines, Reduces nausea, Stimulates the appetite and Relieves depression. (SEE also “Did We Get it Wrong”)

StrainA specific variety of a plant species.

TDS – Total Dissolved Solids (TDS) is the best measurement of the nutrient concentration of a hydroponic solution. To estimate TDS, one uses a meter that measures the Electric Conductivity (EC) of a solution, and then converts the number to parts per million (ppm).

THC THC is an abbreviation for tetrahydrocannabinol. It is the most well-known and most abundantly available cannabinoid in marijuana plants. THC is also the component in marijuana that is responsible for the psychoactive effects, or the “high”.  Research has shown THC to be an effective medical treatment for a range of conditions. There is no lethal dose of the compound in its natural form.

TinctureA liquid cannabis extract usually made with alcohol or glycerol that is often dosed with a dropper. Tinctures can be flavored and are usually placed under the tongue, where they are absorbed quickly. Effects can be felt within minutes.

TopicalA type of cannabis product where the active properties of the flowers have been extracted and added to a product such as a lotion or a cream that’s applied and absorbed through the skin.

Topping – A plant training techniques that involve “pinching” or cutting off some of the top growth between nodes to achieve better use of the available light, create more colas, and achieve bigger yields. (SEE also FIM.)

TrichomeThe resin production glands of the cannabis plant.