Definition - What does Fan Leaves mean?
Filled with flavor, resin, and other phytonutrients, cannabis fan leaves are the large, primary leaves of the plant. (The small leaves that poke out of the cola are called the sugar leaves.)
Though the fan leaves are the most under-recognized part of the cannabis plant, they can still be put to use in various different ways. For example, fan leaves can be used to judge the overall health of the marijuana plant. By carefully observing the growth process of the fan leaves, growers can be warned about pesky insects, caterpillar bites, aphids, and more.
When the leaves begin to wilt, it means that the plant has an insufficient or an over sufficient water supply, and when the leaves begin to curl and go brown, the plant has likely experienced nutrient burn, a sign that a grower needs to lay off or flush their soil as a last resort.
Hydrolife explains Fan Leaves
While balancing the temperature, humidity, lighting, and nutrients of a growroom is a must, it is not enough to produce good-quality yields. In order to maximize yields, excess fan leaves need to be removed in order to create an airflow to the central, denser areas of the canopy. This is called 'plant canopy management' by professional growers, and, while it can be a time-consuming process, it is extremely important for many strains.
A majority of the marijuana plant’s medicinal and psychoactive potential lives in the cola; however, the fan leaves also contain some of the vital cannabinoids and acids that give the plant therapeutic value. Even so, the fan leaves only have trace amounts of these compounds.