Complete Greenhouse Glossary

A traditional structure with two sides meeting at a triangular peak. Excellent for shedding snow and rain, making it ideal for colder or harsher climates.

A structure built against an existing building wall, utilizing thermal mass to help regulate temperature while saving space and construction costs.

A standalone structure independent of other buildings, offering excellent light exposure and airflow from all sides with superior ventilation.

A structure of interconnected triangles forming a dome. Exceptionally strong, wind-resistant with excellent diffused light and superior natural insulation.

A structure with pointed, arched roofline combining economic benefits with superior snow-shedding and larger internal air volume for better heat retention.

A simple, arch-shaped structure made of bent pipes covered with polyethylene film. Affordable and flexible but may not withstand extreme weather.

A semi-circular or arched structure that is economical and easy to construct, though with limited usable space near the curved sidewalls.

An ornate style with tall sides and steeply pitched roof for excellent ventilation and light, valued for both functionality and aesthetic appeal.

The base structure that resists loads from frame, snow, and wind. Should extend below frost line with concrete being most durable for permanent structures.

The structural skeleton of the greenhouse that supports the glazing. Common materials include aluminum, galvanized steel, and wood.

The transparent or translucent material covering the greenhouse frame, allowing sunlight to enter. Options include glass, polycarbonate, and polyethylene.

A rigid framework of beams designed to support the roof over wide spans, adding significant strength and allowing support of heavy equipment.

A measure of thermal resistance in glazing and insulation; higher numbers mean better heat retention and lower winter energy bills.

The baseline air temperature inside your greenhouse when fans, heaters, and cooling systems are OFF; use it to decide when to ventilate or add heat.

A unit of measurement for thermal energy, used to quantify the heating or cooling capacity of equipment like greenhouse heaters.

Gentle warmth from heat mats or cables beneath seed trays that speeds germination and root growth—especially in cool weather.

The gap between actual humidity and saturation point; dialling it in drives rapid, disease‑free growth by optimizing transpiration.

Heaters fueled by natural gas or propane, often the least expensive to operate but requiring proper ventilation to exhaust harmful combustion byproducts.

Heaters using electricity to generate warmth. 100% efficient with no ventilation needed, but electricity costs can make them expensive for continuous use.

A heating method that warms surfaces directly through in-floor systems or baseboard heaters, providing more natural heat distribution for plants.

The intentional exchange of indoor and outdoor air—via roof vents, side‑louvres, or exhaust fans—to control temperature, humidity, and CO₂.

The process of cooling and air exchange using natural forces like wind and thermal buoyancy through manually or automatically operated vents.

A fan typically installed in an endwall for mechanical ventilation, actively pulling hot air out while fresh air is drawn in through intake shutters.

A process that cools air through water evaporation, highly effective in hot, dry climates using fan-and-pad or fogging systems.

Woven fabric used to cover greenhouses to reduce sunlight intensity, lower internal temperature, and protect plants from sun scorch.

The total amount of photosynthetically active radiation received by a plant over 24 hours, critical for predicting plant growth and quality.

The range of light spectrum (400-700 nanometers) that plants use for photosynthesis, including blue, green, yellow, orange, and red light.

The measurement of light quantity within PAR range, expressed as μmol⋅m⁻²⋅s⁻¹, used as the standard metric for horticultural lighting intensity.

A plant's physiological response to day and night length that controls flowering, dormancy, and bulb formation in different plant species.

A sterile medium used instead of soil, providing physical support, water retention, and aeration while offering greater control and reducing disease risk.

Natural fiber from coconut husks with excellent water retention and aeration properties, pH closer to neutral than peat moss.

Heated volcanic glass creating lightweight, porous material added to mixes for improved aeration and drainage without holding much water.

Sterile, porous medium made from spun molten rock with excellent water retention and aeration, widely used in hydroponic systems.

Growing plants without soil using nutrient solution dissolved in water, with systems being either aggregate-based or liquid-based.

Advanced hydroponics where roots are suspended in dark chambers and misted with nutrient solution, providing maximum oxygen exposure.

Hydroponic method where plants on floating rafts have roots suspended directly in deep, oxygenated nutrient solution.

Hydroponic system where a shallow, continuous stream of nutrient solution flows down sloped channels over bare plant roots.

Drip irrigation system where plants grow in individual buckets with growing medium, ideal for large vining plants like tomatoes.

Hydroponic system where grow trays are periodically flooded with nutrient solution then drained, ensuring roots receive nutrients and oxygen.

The process of injecting water-soluble fertilizers into irrigation systems, combining water and nutrient delivery for maximum efficiency.

A measure of total dissolved salts in solution, used to monitor nutrient concentration in irrigation water or growing medium.

A measure of acidity or alkalinity (0-14 scale) critical for nutrient availability and plant uptake in growing medium or nutrient solution.

The process by which a seed sprouts and the embryo begins to grow, starting with the emergence of the radicle (embryonic root).

The embryonic first leaf (or leaves) of a seedling that emerges from the germinating seed, often containing stored food reserves.

Exposing seeds to cold, moist conditions to break embryo dormancy and trigger germination, simulating the natural wintering process.

Seed from cross-pollinating two distinct parent lines, often selected for vigor, yield, or disease resistance. Seeds saved will not grow true to type.

A propagation method where stem, leaf, or root pieces are cut from a parent plant and induced to form new roots and shoots.

Joining parts of two plants so they grow as one, combining desirable fruit/flower traits with vigorous or disease-resistant rootstock.

Separating clumping perennial plants into smaller sections, each with roots and shoots, for simple propagation of plants like hostas.

A 7‑10‑day routine of gradually exposing tender seedlings to outdoor conditions so they develop resilience before transplant.

Stress period after moving plants, showing as wilting or yellowing. Minimized by reducing root disturbance and proper hardening off.

Pairing mutually beneficial crops—like basil with tomatoes—to boost flavor, deter pests, attract pollinators, or maximize space.

Sowing or transplanting small batches every few weeks to secure continuous harvest and avoid boom‑and‑bust gluts.

Selective trimming of stems or suckers to improve airflow, light penetration, and fruit quality while keeping plant size manageable.

Snipping off spent blooms so the plant reroutes energy into fresh flowers instead of seed production.

An environmentally sensitive approach combining multiple strategies to manage pests long-term while minimizing risks to health and environment.

The predetermined point where pest population is large enough to cause unacceptable damage, triggering control action. Goal is management, not eradication.

Using living organisms (natural enemies) including predators, parasitoids, and beneficial pathogens to suppress pest populations naturally.

Regular, systematic plant inspection to identify pests and diseases and assess population levels—the cornerstone of any IPM program.

Small, soft-bodied, sap-sucking insects that reproduce rapidly and excrete honeydew that can lead to sooty mold and attract ants.

Tiny arachnids that feed on plant cells causing stippled leaf appearance. In heavy infestations, they produce fine webbing.

Small, white, moth-like insects that congregate on leaf undersides, sucking plant sap and excreting honeydew. Fly up when disturbed.

Very small, slender insects that scrape plant surfaces and suck contents, leaving silvery patches and black specks. Can transmit viruses.

Common fungal disease thriving in cool, humid conditions, causing fuzzy gray-brown mold on flowers, leaves, and stems.

Fungal disease appearing as white, powdery spots on leaf surfaces, thriving in high humidity without requiring free water on leaves.

Soil-borne disease affecting seedlings, causing them to rot at soil line and collapse. Caused by fungi like Pythium and Rhizoctonia.

Computer-based system integrating sensors to monitor conditions and automatically operate equipment to maintain optimal preset conditions.

Greenhouse integrating sensors, IoT, AI, and automation to create fully optimized, self-regulating environment with minimal labor.

Network of interconnected sensors and devices collecting and exchanging data online, enabling remote greenhouse monitoring and management.