Cannabis starts as a seed and takes roughly four to six months to become a finished product, moving through distinct stages of growing, harvesting, drying, and sometimes further processing into oils or concentrates. The journey from seed to shelf involves careful control of light, temperature, and humidity at every step.
How the Plant Grows
Cannabis is a flowering plant with a life cycle that unfolds in four main phases. Germination takes 3 to 12 days, during which the seed cracks open and a small root emerges. The seedling stage follows, lasting 1 to 4 weeks as the first recognizable leaves develop. Then comes the vegetative stage, a period of 1 to 2 months where the plant puts on most of its height and leaf mass. Finally, a brief pre-flowering transition of 1 to 2 weeks signals the plant is ready to produce flowers.
Cannabis is a dioecious species, meaning individual plants are either male or female. Only female plants produce the resin-rich flowers that contain high concentrations of cannabinoids like THC and CBD. Male plants produce pollen sacs instead. If a male pollinates nearby females, the resulting seeded flowers have significantly lower cannabinoid content. In Canada’s regulated system, pollinated cannabis is actually classified as contaminated and can only be used for oil extraction, not sold as flower. For this reason, commercial growers eliminate male plants early and cultivate exclusively unpollinated females.
Triggering the Flowers
In nature, cannabis begins flowering as autumn days shorten. Indoor growers replicate this by switching their lights to a strict 12 hours on, 12 hours off schedule. This uninterrupted darkness is the signal the plant needs to start producing buds. If the dark period is disrupted, even briefly, the plant can revert to vegetative growth.
Once flowering begins, the buds develop over 8 to 10 weeks on average. During this time, tiny mushroom-shaped glands called trichomes form on the flowers and small leaves. These trichomes are where the plant produces and stores its cannabinoids and aromatic compounds.
Knowing When to Harvest
Growers determine harvest timing by examining trichomes under magnification. In their earliest stage, trichomes are clear and glassy, like tiny droplets of water. This means the cannabinoids haven’t fully developed. When the majority turn white or milky, THC and CBD are at peak concentration. If left longer, trichomes shift to amber or golden, which indicates THC is breaking down into a less potent compound that tends to produce heavier, more sedating physical effects rather than strong mental ones.
Most growers aim to harvest when trichomes are predominantly milky white with just a small percentage turning amber. This window is relatively narrow, often just a few days, which is why experienced growers check their plants daily as harvest approaches.
Drying and Curing
Freshly harvested cannabis contains far too much moisture to smoke or store. The drying process typically involves hanging whole branches or trimmed buds in a dark, well-ventilated room for 7 to 14 days. Rushing this step with high heat degrades the flavor and potency of the final product.
After drying, the buds move into sealed glass jars for curing. This slower process takes two to three weeks at around 70°F with 50% relative humidity. During curing, residual moisture redistributes evenly through the flower while remaining chlorophyll breaks down, which smooths out the taste. Growers open the jars briefly each day, a practice called “burping,” to release excess moisture and refresh the air inside. Well-cured cannabis has a noticeably smoother flavor and more complex aroma than flower that was only dried.
Decarboxylation: Activating the Compounds
Raw cannabis doesn’t actually contain much active THC. Instead, the plant produces an acidic precursor that only converts into the psychoactive form through heat. Smoking or vaporizing does this instantly, but edibles and oils require a separate heating step called decarboxylation. This typically involves baking ground flower at around 230°F (110°C) for 35 to 50 minutes. The exact timing varies, and going too long or too hot can start degrading the very compounds you’re trying to activate.
How Concentrates and Oils Are Made
Many cannabis products go well beyond dried flower. Concentrates strip cannabinoids and aromatic compounds away from the plant material, resulting in products that are far more potent than flower alone. There are two broad approaches: solvent-based and solventless.
Solvent-Based Extraction
The most common commercial method uses supercritical carbon dioxide, or CO2. In this process, CO2 is pressurized and heated until it enters a state where it behaves like both a liquid and a gas simultaneously. In this form, it passes through cannabis plant material and dissolves the cannabinoids and aromatic compounds. When the pressure is released, the CO2 simply evaporates back into a gas, leaving behind a concentrated oil with no solvent residue. This is why it’s considered one of the cleanest extraction methods available.
By adjusting temperature and pressure, processors can even target specific cannabinoids. CBD dissolves more readily at lower pressures, while THC requires higher pressures, which makes it possible to separate the two in a multi-step process.
Ethanol is another widely used solvent. After an initial extraction, the crude oil often goes through a refining step called winterization: the oil is mixed with cold ethanol, which causes plant waxes and fats to solidify and fall out of the solution. These are then filtered away, sometimes through multiple rounds, to produce a cleaner final product.
Solventless Methods
Rosin is the most popular solventless concentrate. It’s made by applying heat and pressure to cannabis flower, kief, or hash using a specialized press. The combination forces the resin out of the plant material, producing a sticky, translucent concentrate without any chemicals involved. Typical pressing conditions range from 600 to 1,000 PSI for flower and 300 to 700 PSI for hash, with lower pressures generally preserving more of the delicate aromatic compounds. The quality of the input material matters more than any other variable. Low-quality flower produces low-quality rosin regardless of technique.
Testing and Quality Control
In legal markets, cannabis must pass laboratory testing before it reaches consumers. Testing screens for potency (how much THC and CBD the product contains), pesticide residues, heavy metals, and microbial contamination. For medical cannabis products in New York, for example, total bacteria must fall below 10,000 colony-forming units per gram and total yeast and mold below 1,000 per gram. Products that fail any of these tests cannot be sold.
Proper drying, curing, and storage all play a role in keeping microbial counts low. Cannabis that retains too much moisture becomes a breeding ground for mold, which is one reason the curing process is so carefully controlled in commercial operations.