Plant density is how many plants occupy a given area, usually given as plants per square metre (1 m² = 10.76 ft²). It interacts with veg time: few large plants and many small plants can fill the same canopy, the first by growing longer, the second by numbers.
In practice
Typical ranges: one to four plants per m² for trained SCROG or mainlined plants; about 9-20 per m² for sea of green clones. In a study of drug-type medical cannabis, higher density increased yield per area while reducing yield per plant and lowering the uniformity of cannabinoid content between plants. Higher density also means more clones, more stems, and denser air under the canopy, which raises humidity and mould risk.
For home growers the deciding factor is often the law: many places cap plant numbers, so fewer, larger, well-trained plants make sense. Check local rules.
Don't confuse with
- Plant count limits: a legal cap on the number of plants; covered as a legal term.
- Canopy area: the area itself; density divides plant count by it.
Veg time is how long a photoperiod plant is kept in vegetative growth under long days before being flipped to flower, which largely sets its final size.SCROG (screen of green) trains a few plants under a horizontal net, tucking shoots so the canopy forms a flat, evenly lit layer of many tops.SOG (sea of green) grows many small plants at high density with little or no veg time, each making one main cola, to shorten the cycle.Medical and adult-use cannabis are separate legal channels: medical access depends on authorisation by a health professional, adult-use on age alone.A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.A plant count limit caps how many cannabis plants a person, household, patient or licence holder may have, and defines what counts as a plant.The canopy is the top layer of foliage and buds across a grow, the surface that intercepts most of the light and where yield is mostly made.Yield is the dry weight of usable flower harvested, usually expressed per plant, per square metre of canopy (g/m²) or per watt of light (g/W).
