Without disclosing the location, my visit to an indoor cannabis growing operation.
Crops are turned around every 12 weeks, this involves the growing to drying process, producing 4 yields annually. The result is a nicely balanced product that ensures you get what you were seeking in the first place.
Cannabis needs certain conditions to flourish.
Growth medium
Soil is required, except for cannabis grown with hydroponics or aeroponics
Warmth
The optimal day temperature range for cannabis is 24 to 30 °C (75 to 86 °F). Temperatures above 31 °C (88F) and below 15.5 °C (60F) seem to decrease THC potency and slow growth. At 13 °C (55F) the plant undergoes a mild shock, though some strains withstand frost temporarily.
Light
Light can be natural (outdoor growing) or artificial (indoor growing).
Under artificial light, the plant typically remains under a regime of 16–24 hours of light and 0–8 hours of darkness from the germination until flowering, with longer light periods being conducive to vegetative growth, and longer dark periods being conducive to flowering. However, generally Cannabis only requires thirteen hours of continuous light to remain in the vegetative stage.
For optimal health, Cannabis plants require a period of light and a period of dark. Typically, flowering is induced by providing at least 12 hours per day of complete darkness. Flowering in cannabis is triggered by a hormonal reaction within the plant that is initiated by an increase in length of its dark cycle, i.e. the plant needs sufficient prolonged darkness for bract/bracteole (flowering) to begin. Some Indica varieties require as little as 8 hours of dark to begin flowering, whereas some Sativa varieties require up to 13 hours.
Water
Watering frequency and amount is determined by many factors, including temperature and light, the age, size and stage of growth of the plant and the medium’s ability to retain water. A conspicuous sign of water problems is the wilting of leaves. Giving too much water can kill cannabis plants if the growing medium gets over-saturated. This is mainly due to oxygen not being able to enter the root system. Anaerobic bacteria start to accumulate due to waterlogged, stale conditions. They begin to consume plant roots, beneficial(aerobic) bacteria, as well as nutrients and fertilizer. When using soil as a growth medium, the soil should be allowed to dry adequately before re-watering.
Humidity
Humidity is an important part of plant growth. Dry conditions slow the rate of photosynthesis. Ideal levels of humidity for optimal growth are 40%.
Nutrients
Nutrients are taken up from the soil by roots. Nutrient soil amendments (fertilizers) are added when the soil nutrients are depleted. Fertilizers can be chemical or organic, liquid or powder, and usually contain a mixture of ingredients. Commercial fertilizers indicate the levels of NPK (nitrogen, phosphorus, and potassium). In general, cannabis needs more N than P and K during all life phases. The presence of secondary nutrients (calcium, magnesium, sulfur) is recommended.
Because Cannabis’ nutrient needs vary widely depending on the variety, they are usually determined by trial and error and fertilizers are applied sparingly to avoid burning the plant.