Roots to terms

— A —

24/0 light cycle

A continuous light cycle used during Germination and Early Vegetation stages to maximise growth.

Abiotic factors

Non-living environmental factors (e.g., temperature, humidity, light) affecting plant growth.

Abiotic stress

Stress caused by non-living factors such as temperature extremes, drought, or nutrient imbalance.

Aerated compost tea

A nutrient-rich liquid derived from compost, aerated to stimulate beneficial microorganisms.

Aeration

The process of introducing air into soil or substrate to enhance root oxygen availability.

Aeroponic cloner

A device used to propagate clones in an aeroponic system by misting cuttings with nutrient-rich water.

Aeroponics

A method of growing plants where roots are suspended in air and misted with nutrient solution.

Air flow

Measured in cubic metres per hour (m³/h), indicating the volume of air circulating in the grow space.

Air pruning

A root pruning method using exposure to air, promoting healthy root growth.

Air stone

A device used in hydroponic systems to create bubbles, improving oxygen levels in the nutrient solution.

Apex

The tip of the plant where the most vertical growth occurs, often removed during topping.

Autoflowering

Cannabis varieties that flower based on age rather than light cycles, usually maturing in 8–12 weeks.

Automation

Technology used to automate cultivation processes, such as watering and lighting.

Auxins

Plant hormones regulating cell elongation, primarily concentrated in the plant’s growing tips.

— B —

Backcrossing

A breeding technique where a hybrid is crossed with one of its parent plants to stabilise traits.

Balanced spectrum

A light spectrum containing equal amounts of red, blue, and white light, suitable for all growth stages.

Bentonite clay

A soil amendment that improves drainage and retains nutrients in organic cultivation.

BHO (Butane Hash Oil)

A cannabis concentrate extracted using butane, known for its high potency and use in edibles or other extracts.

Bloom enhancers

Supplements rich in phosphorus and potassium designed to increase the size and density of cannabis buds.

Blooming

The flowering phase of cannabis plants, during which they produce buds.

Brix level

A measure of sugar content in plant sap, used to evaluate plant health and nutrient absorption efficiency.

Bud

The flower of the cannabis plant, rich in cannabinoids like THC and CBD, typically used for consumption.

Bud rot

A fungal disease caused by Botrytis cinerea, leading to the decay of cannabis buds.

Buffer zone

A layer of substrate or water surrounding roots that stabilises pH and nutrient availability.

— C —

Calcium deficiency

A nutrient deficiency causing brown spots, distorted growth, and weak stems.

Calyx

A small structure in female cannabis flowers surrounding the pistils, forming the bud.

Cannabidiol (CBD)

A non-psychoactive cannabinoid known for its therapeutic properties, such as pain relief and anti-inflammatory effects.

Cannabigerol (CBG)

A minor cannabinoid known as the “mother cannabinoid” since it serves as a precursor to THC and CBD.

Cannabinoids

Chemical compounds in cannabis, like THC and CBD, that interact with the body’s endocannabinoid system.

Cannabis phenohunting

The process of growing multiple seeds of the same strain to identify and select the best-performing phenotype.

Canopy

The upper layer of leaves, often trained for even light distribution and airflow.

Canopy temperature

The temperature at the top of the plant canopy, crucial for managing light and heat levels.

Carbon filter

A device using activated carbon to remove odours from the grow space.

CBDA (Cannabidiolic acid)

The acidic precursor of CBD, known for its anti-inflammatory and potential therapeutic properties.

Chloramine

A chemical used for water disinfection, more stable than chlorine but harder to remove.

Chlorine

A chemical used for water disinfection, which can evaporate or be neutralised before use in cultivation.

Chlorophyll

The green pigment in plants essential for photosynthesis.

Chloroplasts

Structures in plant cells where photosynthesis occurs, converting sunlight into sugars.

Chlorosis

Leaf yellowing due to a lack of chlorophyll, typically caused by nutrient deficiencies or stress.

Clone

A cutting from a mother plant used to produce a genetically identical new plant.

Closed loop system

A cultivation or extraction system where materials are continuously reused to minimise waste.

CO₂ ratio

The concentration of carbon dioxide in the air, usually measured in parts per million (ppm).

Coco (Coco Coir)

A natural substrate made from coconut fibres, ideal for controlled cultivation.

Colas

The main flowering sites of a cannabis plant, often the largest and most resinous buds.

Companion lighting

Low-intensity lighting used to extend daylight hours or support shaded areas.

Companion planting

The practice of growing other plants alongside cannabis to deter pests or enhance soil health.

Compost tea

A nutrient-rich liquid made from compost, used to feed cannabis plants.

Composting

The process of recycling organic materials into nutrient-rich compost for cannabis cultivation.

Crimping

A plant training technique involving gentle bending to encourage lateral growth.

Cytokinins

Plant hormones promoting cell division and affecting shoot and leaf growth.

— D —

Dark cycle

The dark period in a light cycle, essential for flowering in photoperiod cannabis varieties.

Decarboxylation

The process of heating cannabis to activate cannabinoids, such as converting THCA into THC.

Deciduous traits

Characteristics of plants that naturally shed their leaves during ripening.

Defoliation

The removal of leaves to improve airflow and light penetration to lower parts of the plant.

Drip irrigation

A precise watering system delivering water and nutrients directly to roots in controlled amounts.

Dry amendments

Solid, slow-release fertilisers added to soil, often used in organic cultivation.

DWC (Deep WaterCulture)

A hydroponic system in which plant roots are submerged in an oxygenated nutrient solution.

— E —

Ebb and flow

A hydroponic system periodically flooding and draining the root zone to promote aeration.

EC (Electrical Conductivity)

A measurement of nutrient concentration in hydroponic solutions, expressed in milli Siemens per centimetre (mS/cm).

Electrical hazard

A risk arising from improper wiring or the presence of water near electrical components.

Energy distribution

A plant’s natural process of allocating energy to various parts, influenced by pruning and training.

— F —

F1 hybrid

A first-generation hybrid resulting from crossing two genetically distinct cannabis varieties.

Fan leaves

Large cannabis leaves used for photosynthesis, often removed during pruning.

Feminisation

A process used to produce seeds that develop into female plants only, often using chemicals like colloidal silver.

Feminised seeds

Seeds specifically bred to produce only female cannabis plants, eliminating the chance of males.

Fertilisers

Substances that provide nutrients to plants for growth.

Flavonoids

Plant compounds found in cannabis that contribute to flavour, aroma, and potential health benefits.

Flush-to-waste system

A hydroponic system where excess nutrient solution is drained and discarded instead of being recycled.

Flushing

The process of using plain water to remove excess nutrients from the substrate.

Foliar spray

Applying nutrients or pesticides directly to the plant’s leaves.

— G —

Germination

The initial stage of growth where seeds sprout and form seedlings.

Greenhouse effect

Heat accumulation caused by trapped sunlight in a closed space, relevant for outdoor and greenhouse cultivation.

Greenhouse growing

The cultivation of cannabis in a controlled environment using natural and supplemental lighting.

Grinder

A tool used to break down cannabis flowers for consumption or processing.

Grow medium

The substrate in which plants grow, such as soil, coco coir, or hydroponic systems.

— H —

Harvest window

The optimal time period for harvesting cannabis, determined by trichome colour and flower development.

Heat map

A visual representation of temperature distribution in a grow space to identify hotspots.

Heat stress

A condition caused by excessive heat, with symptoms like leaf curling, yellowing, or wilting.

Hermaphrodite

A cannabis plant that produces both male and female flowers, often due to stress or genetic predisposition.

HST (High Stress Training)

Plant training techniques, such as topping or bending, that redirect growth and increase yield potential.

Humic acids

Organic compounds that improve soil structure and nutrient uptake by cannabis.

Humidity

The amount of moisture in the air, ideally kept between 40–70% depending on growth stage.

Humidity dome

A cover placed over seedlings to maintain high humidity during early growth stages.

Hydroponic solution

A liquid mixture of nutrients used in soilless cultivation systems.

Hydroponics

A method of growing plants without soil, using water-based nutrient solutions instead.

— I —

Integrated Pest Management (IPM)

A strategy combining biological, cultural, and chemical controls to manage pests effectively with minimal harm.

Intermodal spacing

The distance between nodes on a stem, influenced by light intensity and plant genetics.

Internode

The space between two nodes on a stem, often used to assess plant health and growth.

Interveinal chlorosis

Yellowing between leaf veins, often caused by magnesium or iron deficiencies.

IPM

see Integrated Pest Management (IPM)

Iron deficiency

A nutrient deficiency causing yellowing of new leaves, often due to pH imbalance or poor water quality.

— K —

Kief

A resinous substance collected from cannabis flowers, used for hash production or as an additive.

— L —

Leaf miner

A pest that burrows inside leaves, creating visible tunnels and reducing photosynthesis.

Light leakage

Unwanted light entering the grow area during dark cycles, potentially disrupting flowering.

Light spectrum

The range of wavelengths of light provided to plants, including red, blue, and white light for different growth stages.

Limonene

A common cannabis terpene with a citrus aroma, known for its uplifting effects.

Living soil

Soil rich in organic matter, beneficial microorganisms, and fungi, supporting a self-sustaining ecosystem.

LST (Low Stress Training)

A training method designed to shape the plant canopy and optimise light exposure without causing stress or damage.

— M —

Macro nutrients

The primary nutrients required in large amounts: nitrogen (N), phosphorus (P), and potassium (K).

Mainlining

A structured plant training method combining topping and LST to create a symmetrical canopy.

Male pollen

Reproductive cells produced by male cannabis plants, used in breeding.

Microbes

Beneficial bacteria and fungi that support plant nutrition and health.

Microclimate

The localised climate within the grow space, influenced by factors such as ventilation and lighting.

Micronutrients

Nutrients required in small quantities, such as iron, zinc, manganese, and copper.

Monosilicic acid

A silicon supplement that strengthens plant cell walls and boosts cannabis resilience.

Mulching

Applying a layer of organic material to the soil surface to retain moisture and suppress weeds.

Mycorrhizae

Beneficial fungi forming a symbiotic relationship with roots, improving nutrient uptake.

Myrcene

A common cannabis terpene with earthy, musky aromas and calming effects.

— N —

Negative pressure

A condition in which more air is removed than supplied, preventing odour leaks from grow spaces.

Nitrogen toxicity

A condition caused by excessive nitrogen, characterised by dark green leaves and stunted growth.

Node

The point on a cannabis stem where leaves, branches, or flowers grow.

Nutrient burn

Leaf scorching caused by over-application of nutrients.

Nutrient lockout

A condition where nutrients become unavailable due to pH imbalance or salt build-up.

Nutrient precipitation

A process where nutrients fall out of solution, rendering them unavailable to plants.

— O —

Open pollination

A natural breeding method where plants are pollinated without human intervention.

Osmosis

The movement of water through a semi-permeable membrane, essential for nutrient uptake by roots.

Overdrying

A condition where cannabis buds lose too much moisture during drying, becoming brittle and less aromatic.

Overfeeding

Applying too many nutrients, leading to nutrient burn and poor plant health.

Overwatering

A common issue where excessive watering causes wilting, root rot, and slow growth due to waterlogged soil.

Overwatering

Excessive watering causing wilting, root rot, and slow growth due to saturated soil.

— P —

PAR (Photosynthetically Active Radiation)

The spectrum of light (400–700 nm) used by plants for photosynthesis.

Parabolic reflector

A type of light reflector that maximises light distribution and intensity across the canopy.

Pesticide drift

The unwanted transfer of pesticides to neighbouring plants or areas due to wind or improper application.

pH (potential Hydrogen)

A scale measuring acidity or alkalinity, crucial for nutrient availability to plants.

pH adjusters

Chemicals like pH-Up and pH-Down used to balance acidity in water or nutrient solutions.

Phenotype

The observable characteristics of a cannabis plant, influenced by genetics and environment.

Phloem

Vascular tissue in plants that transports sugars and nutrients from leaves to other parts.

Phosphorus deficiency

A nutrient deficiency causing purple stems, delayed growth, and poor flower development.

Photoinhibition

A condition where excessive light intensity reduces photosynthetic efficiency, often caused by high-intensity lights.

Photoperiod

The duration of light and darkness a plant receives, essential for regulating growth phases in photoperiod strains.

Photosensitivity

The plant’s sensitivity to light cycles, critical for triggering flowering in photoperiod strains.

Pinching

A gentle training method that redirects growth by slightly damaging the plant’s internal tissue.

Pistil

Hair-like structures on female cannabis flowers that catch pollen.

Potassium deficiency

A nutrient deficiency causing yellowing and browning on leaf edges, and weak stems.

ppm (parts per million)

A unit of measurement for the concentration of nutrients in water, essential for precise feeding in cultivation.

Pre-flowering stage

The transition phase between vegetative growth and flowering, when plants start showing their sex.

Propagation tray

A flat tray used for germinating seeds or rooting cuttings, often paired with a humidity dome.

Pruning

The practice of removing unwanted growth to direct the plant’s energy to desired areas.

— R —

Relative humidity (RH)

The amount of water vapour in the air relative to the maximum it can hold at a given temperature.

Resin

A sticky substance produced by cannabis trichomes, containing cannabinoids and terpenes.

Resin glands

Structures in cannabis trichomes responsible for cannabinoid and terpene production.

Ripening

The final flowering stage when cannabis buds mature, reaching peak potency and flavour.

Rockwool

A cultivation material made from spun rock fibres, used in hydroponics for water retention and aeration.

Root ball

The mass of roots and soil or substrate surrounding the base of a plant.

Root bound

A condition where roots outgrow their container, restricting further growth.

Root exudates

Compounds secreted by roots to interact with soil microorganisms and enhance nutrient uptake.

Root hairs

Fine extensions of roots that increase surface area for water and nutrient absorption.

Root pruning

Trimming roots to encourage new growth and prevent root overcrowding.

Root zone

The area of soil or substrate where roots interact with nutrients, water, and oxygen.

Roots

Structures that anchor the plant in the substrate, absorb water and nutrients, and interact with soil microorganisms.

Runoff

The water that drains out of the growing medium after watering, often used to measure pH and nutrient levels.

— S —

ScrOG (Screen Of Green)

A training technique using a net to create an even canopy and maximise light exposure.

Seedbank

A business specialising in the sale and storage of cannabis seeds.

Seedling

The growth phase following germination, when the first leaves appear.

Shelf-life

The time a fertiliser or product remains effective under proper storage conditions.

Side lighting

Supplemental lights placed around plants to improve growth of lower buds.

Silica additives

Supplements enhancing cell wall strength and plant resilience, especially against stress.

Soil moisture

The amount of water present in the soil or substrate.

Spider mites

Tiny pests feeding on plant sap, causing damage and reduced yields.

Stem

The main structural support of the plant, transporting water, nutrients, and sugars between roots and leaves.

Stigma

Hair-like part of the pistil on female flowers that captures pollen.

Stomata

Tiny openings on leaves regulating gas exchange, including CO₂ uptake and water release.

Stress testing

Techniques used to assess a plant’s resilience, often in breeding for hardier strains.

Sugar leaves

Small, trichome-covered leaves within buds, often used for extracts or edibles.

Super cropping

A high-stress training method involving bending or pinching branches to boost yields and redirect growth.

— T —

Taproot

The main root developed during germination, forming the basis of lateral root systems.

Temperature

An environmental factor measured in degrees Celsius (°C) or Fahrenheit (°F).

Terpene profile

The unique combination of terpenes in a cannabis strain, contributing to its aroma, flavour, and effects.

Terpenes

Aromatic compounds in cannabis contributing to its flavour, aroma, and effects.

Tetrahydrocannabinol (THC)

The psychoactive compound in cannabis responsible for its euphoric effects.

THCA (Tetrahydrocannabinolic Acid)

The non-psychoactive precursor form of THC found in raw cannabis.

Time-release fertilisers

Fertilisers designed to release nutrients over time, often less suitable for cannabis cultivation.

Tissue culture

A propagation method using small tissue samples for cloning plants under sterile conditions.

Top dress

Applying fertilisers or soil amendments to the surface of the substrate for gradual release.

Topping

A high-stress training method involving cutting the plant’s main apex to encourage lateral growth.

Trichome heads

The bulbous tips of cannabis trichomes containing the highest concentrations of cannabinoids and terpenes.

Trichomes

Resinous glands on cannabis flowers and leaves that produce cannabinoids and terpenes.

— V —

Vapour barrier

A layer used during grow space construction to prevent moisture leakage or ingress, maintaining stable humidity.

Vegetative growth

The growth phase where cannabis focuses on developing leaves and stems, building structure for flowering.

Vertical growing

A method of cultivation where plants are grown on vertical racks to maximise space utilisation.

VPD (Vapour Pressure Deficit)

A measure balancing temperature and humidity to optimise plant transpiration and growth.

— W —

Water flow

Measured in litres per hour (L/h), useful for irrigation systems.

Water hardness

The concentration of dissolved calcium and magnesium in water, affecting pH stability and nutrient mixing.

Wet trimming

The process of trimming cannabis immediately after harvest, before drying.

Wet weight

The weight of cannabis buds immediately after harvest, before drying and curing.

Winterisation

A post-extraction process removing fats, waxes, and impurities, producing cleaner concentrates.

μmol/m²/s

Micromoles per square metre per second, a unit for measuring photosynthetically active photon flux density (PPFD).