An even canopy is a flat, level layer of tops. Light intensity falls off with distance from the fixture and varies across the footprint, so a top 30 cm (12 in) below its neighbours can receive a fraction of their light. Flattening the canopy brings every bud site into the same light band.
In practice
Growers level a canopy with LST, topping, mainlining, SCROG and supercropping the tallest tops in early flower. The aim is usually a spread of no more than about 10-15 cm (4-6 in) between the highest and lowest main colas. Research on large medicinal cannabis plants found that plant architecture affected how uniform cannabinoid content was between top and lower buds, which supports the logic of training for evenness.
A PAR meter reading at several points across the canopy shows how even it really is.
Don't confuse with
- Uniform PPFD: even light from the fixture; you need both an even light map and an even canopy.
- Uniform plants: same genetics and size; helps, but is not the same as a level canopy.
LST (low-stress training) bends and ties stems so the plant grows wide and flat, exposing more bud sites to light without cutting or breaking tissue.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.Supercropping is gently crushing a stem's inner tissue between the fingers and bending it over, so the branch lowers, toughens at a knuckle and stays productive.The dense, elongated cluster of flowers that forms at the end of a stem or branch; the main cola tops the leader.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.Photosynthetically active radiation: light in the 400–700 nm waveband that plants use for photosynthesis, counted in photons rather than brightness.Photosynthetic photon flux density: the number of PAR photons landing on one square metre each second, in µmol/m²/s; the standard measure of light intensity at the canopy.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.Mainlining is a training method that tops a plant low, removes lower growth and splits it symmetrically into a set number of evenly sized main colas.
