Indoor Growing Dictionary
Find the definition to all grower terms
Hi there and welcome to Free the Tree’s glossary!
In this article we decided to group together de definition of all the commonly used terms in the marijuana growing community, hope it’ll help out!
If you know right where you’re going here’s a link to each section
To draw or take in: Rootlets absorb water and nutrients.
AC (Alternative current)
An electric current that reverses its direction at regularly occurring intervals: Modern Homes use AC electric.
A sour substance; An acidic or sour soil has a low pH, ranging from 0 to 6.9.
A Hydroponic system that actively moves the nutrient solution
Heavy clay soil that drains slowly. Adobe is not suitable for container gardening.
Aeration (oxygenating the soil)
To supply soil and roots with air or oxygen. This can be done well using Air Pots
Roots that grow from unusual spots as on the pericycle (stem) or endodermis of an older root.
Auxin levels may influence this type of root growth.
Growing plants by misting roots suspended in the air
A substrate that is of nearly uniform size and used for the inert hydroponic medium.
Having to do with the economics of agriculture
Refers to a substance with a pH ranging from 7.1 to 14
A process in which an alkyl group is substituted or added to a compound
Two genes, each of which occupies the same position or locus on two homogeneous chromosomes.
Can be either organic or mineral based: Amendments change the texture of a growing medium (ex: adding water beads to the soil)
The unit used to measure the strength of an electric current.
ex: A 20 amp circuit will be overloaded when drawing more than 16 amps
Androecious plants are defined by having staminate (male) flowers
An androecious population consist only of males, also called “all-male” populations.
Pollinated by wind-dispersed pollen.
Marijuana is a anemophilous plant, meaning that it doesn’t depend on a pollinating insects.
A plant that normally completes its entire cycle of life in one year or less.
Weed is an annual plant
Container for luminous gases; Houses the arc in an HID lamp
Reproducing using non-sexual means such as taking cuttings from a parent plant.
These means will produce exact genetic replicas of the parent plant (also called clones)
Classification of plant hormones. Auxins are responsible for foliage and root elongation.
Very small, one-celled plant that does not contain any chlorophyll.
Common term given to marijuana seeds from an unknown origin, generally found in a bag of marijuana
A stabilizing unit that regulates the flow of electricity and starts an HID lamp. A ballast is composed of a transformer and a capacitor.
Insects that feed, or keep away, marijuana Pests.
Lady bugs are the perfect example when fighting a thrips infestation
To decompose through natural bacterial action. Substances made of organic matter can be broken down naturally.
The production of a chemical compound by a plant. Plants produce O2 (oxygen) through biosynthesis.
Household laundry bleach can be used in a mild water solution to sterilize grow rooms and as soil fungicide.
High-nitrogen organic fertilizer made from dried blood.
A plant that starts yielding flowers. When Marijuana enters the flowering stage she starts to bloom.
Fertilizer high in Potassium and Phosphorus (KP) which increases the flower yield and weight
A very short or dwarfed plant. Can be done to a mother plant in order to maintain her.
Small spur-like foliage that grows from the plants stem; this is the point from which flowers emerge.
Electrical circuit box having on/off switches rather than fuses. The main breaker box is also called a service panel.
To sexually propagate cannabis under controlled circumstances.
There are 2 possible definitions to this term
- A small, undeveloped stem or shoot.
- A collection of flowering calyxes on a branch
A withering condition that attacks flower buds.
The most common type of bud blight in cannabis is mold
A substance that reduces the shock and cushions against fluctuations. Most fertilizers contain buffer agents.
Outer glass envelope or jacket that protects the arc tube of an HID lamp
A ball-shaped, resin producing plant hair without a stalk.For more check out our in-depth article on Trichomes
Tissue made of undifferentiated celles produced by rooting hormones on plant cuttings.
The pod harboring male or female cannabis reproductive organs.
A layer of cells which divides and differentiates into xylem and phloem and is responsible for growth.
Scientific family to which Cannabis (Marijuana/Weed/Ganja) and Humulus (hops) belong to.
A family of hydrocarbons produced by cannabis. Marijuana is the only plant to produce these elements.
Proportional ratio and levels of major cannabinoids found in a specific strain of cannabis
Scientific name for marijuana
Capitate Stalked Trichome
Resin producing plant hair without a stalk. This trichome contains high levels of THC.For more check out our in-depth article on Trichomes
Neutral compound of carbon, hydrogen and oxygen which is mostly formed by green plants.
Sugar, starch and cellulose are carbohydrates
Carbon Dioxide (CO²)
A colorless, odorless, tasteless gas in the ai; necessary for the life and development of a plant.
A substance that destroys, kills or eats away by chemical activity
This compound, produced by the trichomes once they’ve started to deteriorate is on the the main components studied in Medical Marijuana.
It does not have psychoactive effects but is known for prolonging the high.
Second most abundant cannabinoid in recreational marijuana
Base structural unit of plants which contain a nucleus, a membrane and chloroplasts.
A complex carbohydrate that stiffens a plant. Outdoor stems contain more stiff cellulose that indoor plants.
When you cut the stem of the plant, the white section inside is cellulose
Combining nutrients in an atomic ring that is easy for plants to absorb
Chimera (aka Chimaera)
There are 2 possible definitions depending on the context
- A plant or organism with tissue from at least 2 genetically distinct parents
- A fire-breathing female monster most often portrayed as a lion, goat and serpent composite
(I think you’re looking for the 1st ^^)
The green photosynthetic matter present in plants.
Chlorophyll is found in the chloroplasts of a cell and is necessary for photosynthesis
The condition of a sick plant with yellowing leaves due to inadequate formation of chlorophyll. Chlorosis is caused by a nutrient deficiency, generally iron or a pH imbalance
Soil made of very fine organic and mineral particles.
Clay drains slowly and is not suitable for container gardening.
There are two possible definitions to this:
- A rooted cutting of a plant
- Asexual propagation of the plant
In both cases a close has the exact same properties as the mother plant.
A technique used to increase the grow rooms or greenhouses atmosphere by adding CO² in order to speed up growth.
Mexican and North-american term used to talk about a marijuana flower top.
Poisonous alkaloid from the autumn crocus used n plant breeding to introduce polyploid mutations
Generally for marijuana dangerous cold temperatures are around 10°C (50°F)
The band of colors, measured in nm emitted by the light source.
A coloring agent that is added to many commercial fertilizers so the horticulturist knows there is fertilize in the solution. For example, Peters uses a blue color tracer
Soil condition that results from tightly packed soil which limits aeration and root penetration.
Planting friendly plants around marijuana in order to repel pests or increase resistances to deficiencies.
This is generally done in outdoor plantations.
The most common examples are garlic and marigolds
Mixture of decayed organic matter high in nutrients. Compost must be well rotted before use.
When it’s too young the decomposition actually uses up Nitrogen, which is counter productive. Once the decomposition process has advanced through the stages will be returned to the soil.
The transformer in the ballast is often referred as a core.
Seed leaves. They are the first leaves that appear when the seedling has broken the ground.
Cotyledon’s allow the plant to photosynthesis enough in order to grow the first set of leaves. During the next stages of growth they’ll most likely die off.
Critical Day length
Maximum light hours which will bring about flowering in the marijuana plant.
Fertilizing a plant with pollen from an unrelated individual of te same species
When talking about crystals on marijuana people can be talking about 2 things:
- Resin appearing on the foliage.
- Fertilizers that come in a form of soluble crystals
A contraction of “cultivated variety” which is a strain of plant that has been intentionally created or selected.
This is not a naturally occurring phenomenon.
Cure (Curing marijuana)
Curing marijuana refers to the slow drying process of Marijuana after harvesting.
This step is crucial and as important for the taste and high as the whole growth of the plant.
Thin layer of plant wax (cutin) on the surface of the above ground parts of plants.
The term cutting refers to a growing tip cut from a parent plant for asexual propagation.
The cuttings will be perfect clones of the mother plant
Plant hormones that promote cell division, growth and delays the aging of leaves.
Fungus disease that attacks young seedlings and clones causing stem to rot at its base.
Over-watering is the main cause of damping-off
DC (Direct Current)
A continuous electric current that only flows in one directions.
To rot or decay through organic chemical change.
A period of plant dormancy during which growth or development is suspended or diminished
Double potting is a two-pot transplanting technique that minimizes root disturbance.
To empty soil of excess water.
Good Drainage: A soil with good drainage lets water pass through soil, evenly promoting plant growth.
Bad Drainage: Water stands still in the soil which will drown the roots and eventually make them rot.
Drip Irrigation System
Efficient watering system that employs a main hose with small water emitters letting water drip down onto the soil.
These systems allow a much better and in-depth irrigation of the medium
A line around a plant directly under its outermost branch tips.
Roots seldom will grow beyond the drip line.
Cold, white substance formed when CO² is compressed and cooled.
Dry ice is used to increase CO² levels in grow rooms.
Dry Soil Pockets
Portions of soil that remains dry after watering. You can avoid this by:
- Adding wetting agent (soap) to the water
- Use a slow drip irrigation system
- Wait 15 minutes between each rounds of watering.
Drain hole filled with rocks to receive drainage water.
Elongate (aka the stretch)
To grow in length. Marijuana plants are known to grow strongly the first weeks of the flowering stage. Depending on the strain they can grow up to 200%!For more check out our article on the strech
A bubble of air in the transpiration stream of a cutting which blocks the uptake of water and nutrients.
If this happens the cutting will die.
A young plant developing within the seed. In cannabis, an embryo is derived from a fertilized ovule.
Hydrated magnesium sulfate in the form of white crystalline salts. Adding Epsom salts to your medium will increase the levels of magnesium available to the plant.
Ethane Methyl Sulfonate
A mutagenic chemical that causes changes at the DNA level which will induce genetic mutations.
Growth of a plant in total darkness to increase the chances of root initiation.
First filial generation; These are the offspring of the P1 (1st generation parents) plants.
F1 Hybrid Genaration
Heterozygous first filial generation
Second Filial Generation resulting from a cross between two F1 plants.
Large, fan-like marijuana leaves. In your plant these are the largest leaves that photosynthesis the most but contain low amounts of potency.
Pistillate, ovule, seed or flower producing cannabis plant.
This term is used in two different contexts
- When adding nutrients into the soil or to the foliage of the plant.
- To impregnate (unite) male pollen with a female ovary plant.
Fertilizer burn (aka nutrient burn)
Over fertilization; At first the tips of the leaves start to burn (turn black/yellow) then the leaves curl up and die.
Acronym for “Fuck I missed!” pruning method, check out our guide for more
A shallow container used to start seedlings or clones
A mass of calyxes on a stem, top of bud.
The leaves, or more generally, the green part of a plant.
Misting fertilizer solution which is absorbed by the foliage
Foot Candle Measurement
One Foot Candle (fc) is equal to the amount of light that falls on one square foot of surface located one foot away from a candle.
To fuse or embed nutrients with a glass compound.
Fritted Trace Elements (FTE’s) are long lasting and do not easily seep into the substrate.
A product that destroys or inhibits fungus.
Product that inhibits fungus.
A lower plant (lacking chlorophyll) that may attack green plants: Mold, rust, mildew, mushrooms and bacteria are fungi.
Hindustani term for marijuana now used worldwide.
A class of plant growth hormone used to promote stem elongation.
Removing a strip of bark or crushing the stem of the plant. Girdling limits the flow of nutrients, water and other nutrients. When badly done this can kill a plant or section of the plant.
When done well this can then create a knot which will increase the nutrient intake capacities.
Plant hair gland which secretes resin
Measurement indicating Gallons per Minutes
Insect that preys on aphids, thrips, whiteflies, etc and their larva and offspring. These little are your friends when dealing with an infestation.
Dung from birds, high in organic nutrients. Seabird guano is noted for being high in nitrogen; Bat guano is known for being high in Phosphorus.
An individual plant having all pistillate flowers; This is a reference to a population of all-female plants.
Plantations of marijuana that are destined to be smoked are gynoecious plantations.
Female part of a flower that consists of one or more pistils.
A binary chemical compound of a halogen(s) with an electro-positive element.
Generally used during the vegetative stage in Metal Halide bulbs.
Gradual adaptation of indoor or greenhouse plants to an outside environment.
Depending of the plant or strain this can last from a couple days to weeks.
A psychoactive element formed of compressed resin heads (trichomes) shaken, washed or rubbed from the foliage of the marijuana plant.
Solution of tetrahydrocannabinol with a high THC content made from cannabis.
Fibrous cannabis low in THC used to make a wide range of products, from textile to automobiles.
An individual having flowers of both sexes on the same plant. Meaning that some colas will be male and others female.
Hermaphrodites are more correctly referred to as “intersex”.
Hybrid vigor such that an F1 hybrid falls outside the performance range of the parents with respect to some character or characters. Usually applied to size, rate of growth or general vigor.
High Intensity Discharge lamp. These are types of plants generally used in indoor cultures, Metal Halide during the vegetative stage and High Pressure Sodium during the flowering stage.
The opposition to this are LED lights.
The reflective cover of a lamp..
The abbreviation stamped on some HID bulbs meaning that they may be used in a horizontal position.
Dark, fertile, partially decomposed plant or animal matter. Hums forms the organic portion in the soil.
An offspring from two plants of different breeds, variety or genetic make-up.
Greater strength and health or faster rate of growth in the offspring resulting from the cross-breeding of two gene pools.
Growing plants in nutrient solutions without soil, usually in an inert soil-less mix
Instrument for measuring relative humidity in the atmosphere. A hygrometer will save time, frustration and money.
Indol-eacetic acid is a hormone that stimulates growth.
The process of breeding solely within the seed lot with no external pollen inputs.
Day length required to stimulate flowering.
A product that kills or inhibits insects.
The amount or strength of light energy per unit or area. Intensity decreases the further away from the source of light.
A single individual expressing both staminate and pistillate flowers.
Having sexual characteristics of both the typical male and typical female plant.
To incorporate or add a trait to a given population without otherwise altering the significan characteristic of the population.
K – L
Moroccan word for cannabis plants and flowers. It’s also the Moroccan term for the pollen of the plant.
Kiff is not Hash.
A wild cannabis strain that is not improved by humans
To dissolve or wash out nutrients within the soil by heavy watering. This is generally done when dealing with nutrient burn.
A plant that is abnormally tall with few leaves, this is usually caused by lack of light or space.
Life Cycle of Marijuana
A series of growth stages through which cannabis must pass in its natural lifetime.Check out each step of the Life Cycle of the Marijuana
A device that moves a lamp back and forth or in a circular path across the ceiling of a grow room to provide more balanced light.
Cutting off lower, secondary plant branches to encourage primary growth.
Calcium compounds such as dolomite of hydrated ime that determine or alter soil pH levels; they will also increase Phosphorus levels.
Chemically sensitive paper used to indicate pH levels in colorless liquids.
Organic soil mixture of crumbly clay, silt and sand.
A position on a chromosome where a specific gene is located.
Plural is loci
Measurement of light out-put. 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.
One or all of the primary nutrients N-P-K (nitrogen, Phosphorus or Potassium) or the secondary nutrients Mg (Magnesium) and Ca (calcium).Have an issue with Nutrients? Check out our deficiency guide
Trim leaves and large stems from buds with scissors or fine pruners so the most THC-potent portion remains.
There are 2 possible definitions for this:
- Plant tissue from which new cells are formed
- The active growing tip of a root or stem
Cutting away the growth tip to encourage branching and limit height.
Trace elements necessary for plant health, including Sodium, Iron, Magnesium, Zinc, etc
Having male and female reproductive systems or flowers on the same plant.
Producing only one color, LP sodium lamps are monochromatic lights.
The study of the form and structure of animals and plants.
Female marijuana plant held in vegetative stage and used as a cutting stock to make clones.
A mother plant can come from a seed or can be a clone her-self.
A protective covering for the soil of compost, old leaves, paper, rocks, etc.
The mass of strands that form the root-like part of fungi often submerged in soil or a host body.
Localized death of a section of a plant due to injury or diseases.
One of the 3 essential elements to plant growth.
A joint and/or position on a stem from which leaves, shoots or flowers grow.
Common term used to described 3 of the main nutrients needed for plants, Nitrogen, Phosphorus and Potassium.
Gardening business that grows plants for sale or experimentation.
If you have one near you it’s definitely a good place to get info! 🙂
The term nutrients describes elements that are necessary for the plants. These are composed of macro-nutrients (NPK), secondary elements such as Calcium and Magnesium and trace elements.
All these elements are necessary in order to sustain plant life.
Pollination that occurs naturally as opposed to controlled pollination where no humans interference.
Breeding between individual cannabis plants that are not closely related.
The process of breeding using individuals outside of the family, population or group.
Organism that lives on or in another host organism without benefiting the host; For example Fungus is a parasite.
Hydroponic system that moves the nutrient solution through absorption or capillary action.
A desease*causing micro-organism, especially bacteria, fungi and viruses.
Partially decomposed vegetation, usually moss, with decay due to extreme moisture, cold and acidic conditions.
A plant, such as a tree or shrub, that completes its life cycle over several years.
Marijuana is not a perennial plant.
Amendment of sand or volcanic glass expanded by heat, which aerates the soil or growth medium
A scale from 0 to 14 that measure the acid or alkaline balance in a solution.
From 0 to 6.9 the solution is acidic, 7 is neutral (water) and from 7.1 to 14 is considered alkaline.
For marijuana the best levels of pH are between 6.2 and 6.8.
Electronic or chemical instrument used to measure the acidic or alkaline balance in an environment.Find out how to measure pH levels in your Watering mix
The outward form, characteristic and appearance of a plant determined by the interaction of te individual genotype with the environment
The nutrient and water conducting tissue of vascular plants.
One of the macro-nutrients that promote root and flower growth
The relationship between the length of light and dark in a 24 hour period; This will affect the growth and maturity of marijuana.
The building of chemical compounds from light energy, water and CO²
The environmental response of a plant part toward or away from a light source.
The arrangement of leaves on a stem and the principles that govern such arrangement.
Substance that is toxic to plants normally burning the leaves.
Females having pistils but no functional stamens.
Small pair of fuzzy, white, hairs extending from top of female calyx. The Pistils catch pollen and channel it into contact with the ovule for fertilization.
A dry calyx containing a mature or maturing seed.
Fine, yellow, dust-like microspores containing male genes
Male flower containing pollen
The transfer of male pollen from the anther to the stigma of the same or a different flower to fertilize ovules which produce seeds.
A hybrid plant crossbred for more than one trait.
There are 2 possible definitions here:
- A container used to place growing medium.
- A slang word used in north america for Marijuana
Root system that is bound, stifled or inhibited from normal growth by a too-small container.
One of the macronutrients necessary for plants to live.
Beneficial insect or parasite that hunt down and eat harmful insects.
Trimming branches or parts of plants to strengthen those that remain, or bring shape to the plant.Check out our guide on Plant Training
Natural insecticide made from the blossoms of various chrysanthemums
The part of a plant seedling that develops into a root, the root tip.
Hydroponic system that reclaims the nutrient solution and recycles it.
Rejunevation / Revegetation
A mature plant, having completed its life cycled (flowered) that is stimulated by a new 18 hour photo period in order to reproduce vegetative growth.
Tiny pores that secrete resin
The underground part of a plant. Roots function to absorb water and nutrients as well as anchor a plant in the plant.
Root system that is bound, stifled or inhibited from normal growth by a too-small container.
To weed out inferior, diseased or undesirable plants from a crop, field or population area.
Crystalline compound that results from improper pH or toxic build-up of fertilizer.
Salt will burn plants preventing them from absorbing nutrients.
The shoot (containing buds) that is used for grafting.
SCROG (Screen of Green)
A growing method which involves training cannabis shoots onto a net, trellis or chicken wire.For more check out our in-depth guide on SCROG
To scrape and roughen the surface of a seed. When this is done to seeds with hard outer shells they will germinate faster.
Airtight sealer for plastic baggies used to seal in freshness of pungent marijuana.
This is also very useful to store your buds once you’re done curing them.
Sea of Green (SOG)
A method of growing tightly spaced cloned plants. The clones are flowered very quickly after rooting for a smaller yield per plant but many more plants totalFor more check out our in-depth guide on SOGging
The mature, fertilized ovule of a pistillate plant. It contains a protective shell, an embryo and a food supply.
Given heat and moisture the seed will germinate and grow into a beautiful plant 🙂
Selfing / Self-Pollination
To fertilize with pollen from the same flower or plant; Equivalent
The declining growth stage in a plant or plant part from its prime to death
Sinsemilla is a combination of 2 Spanish words
- Sin: Meaning Without
- Semilla: Meaning seed
This term describes potent marijuana from flowering female cannabis plants kept seedless by preventing pollination in order to promote a high THC content
When talking about plants this refers to the reproduction by means of seed flowering fertilization.
There are 2 types of soaps that can be used when growing indoors
- Wetting agent: Soaps used when watering in order to avoid dry soil pockets
- Insecticidal soaps: Used to get ride of pests
Make sure all the soaps used are biodegradable.
A growing medium made up of mineral particles such as vermiculite, perlite, sand, pumice, etc..
Organic moss is often a component of soilless mixes
An element that can be dissolved in liquids, especially water.
A mixture of two or more solids, liquids or gases, often mixed with water.
Large pieces of perlite, a light mineral, used as soil amendment.
Seed-like offsprings of certain bacteria, fungi, algae and some non-flowering plants
A shoot of a plant which can be found in 2 situations:
- A newly germinated seed breaking the ground
- A new growth of leaf or stem off an existing plant
The male floral organ, bearing the anther which produces pollen to fertilize female flowers.
Male, pollen-producing flower having stamens but no pistils
The tip of the flower’s pistil which receives the pollen
The portion of the pistil on which the pollen germinates
One of a pair of small leaf like appendages found at the base of the leaf stalk of many plants.
Small mouth or nose-like openings on the underside of leaves responsible for transpiration and many other life functions. The millions of stomata must be kept very clear for them to be able to function properly.
The strain of marijuana is based on Ancestry, lineage and phenotype.
Cannabis within the same strain have the same characteristics.
A physical or chemical factor that causes extra exertion by plants, usually by restricting fluid flow to foliage.
Good stress can be applied to the plant in order to increase production, check out our article on plant training for more
The medium on which an organism lives, this can be soil, soilless mix, rock, etc.
Food product for plant.
A reservoir that receives drainage. A drain or receptacle for hydroponic nutrient solutions used for growing cannabis.
A common name for fertilizer high in phosphorus and potassium that promotes flower formation and growth.
The production of a substance, such as chlorophyll, by uniting light energy, elements or chemical compounds.
The main or primary root that grows from the seed. Lateral roots will branch off the taproot.
Classification of plants and animals according to their family relationships
Lukewarm 70-80°F (21-27°C) water. It’s best to water your plants with water at this temperature in order to facilitate chemical processes and ease shock.
Terminal Bud (Apex)
The growth tip of the main stem of branch.
Hydrocarbons found in essential oils (resins) produced by plants.This is one of the elements that gives such a strong aroma to marijuana.
The hard outer covering of a seed.
A psychoactive active ingredient which is the primary intoxicant in marijuana.
This chemical is produced within the trichomes
The amount of time a pesticide or fungicide remains active in the environment.
If you’re using these make sure the toxic life has passed by harvest!
Really it’s best not to use any pesticides during the flowering stage, even neem oil has shown to give side effects.
A give off of water vapor and bi-products via the stomata on leaves
A frame of small boards that trains or supports plants
Method of restricting plant growth or altering its shape and size by tying the plant to a wire or screen (like when scrogging)
Resin-secreting plant hair
Distinct strain or phenotype
Referring to a plants circulatory system which carries sap throughout the body of the plant.
Growth stage in which cannabis rapidly produces new leafy growth, stem and green chlorophyll.
Check out our full article on the vegetative stage
Circulation of fresh air which is fundamental to a healthy indoor garden.
Mica processed and expanded by heat. Vermiculite is a soil amendment and medium for rooting cuttings.
Vitamin that is absorbed by tender root hairs easing transplant wilt and shock
A slang word referring to marijuana.
A compound that 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’s biodegradable.
A whorl is where three or more leaves (or petals) arise from the same point and form a circle around it.
Three or more leaves or branches located at each node along the branches and stems.
The part of a passive watering system that nutrient pass up through in order to be absorbed by the medium and/or roots.
For example a passive hydroponic system uses a wick suspended in the nutrient solution.
There are 2 possible definitions for this term:
- To become limp from a lack of water.
- A plant desease or disorder (over watering for example)
Vascular tissue that transports water and minerals from the roots through-out the stems and leaves.
Alright folks that’s it for this one, don’t hesitate to send a message if you didn’t find what you were looking for!
Until next time, be safe and grow easy