Harvesting cannabis is the final step in cultivation, marking the transition from a growing plant to a usable product. The techniques used directly influence the final quality, potency, and flavor of the flower. Precise timing and subsequent handling methods are necessary to preserve cannabinoids and aromatic terpenes at their peak concentration.
Identifying the Optimal Harvest Window
The decision to harvest is determined by closely examining the plant’s biological indicators, which signal peak maturity. The most accurate way to judge readiness is by monitoring the microscopic, mushroom-shaped glands called trichomes, where cannabinoids and terpenes are produced. These resin glands progress through three distinct color stages: clear, cloudy, and amber.
When trichomes are clear, the plant is still immature and lacks full potency. As the plant matures, the trichomes turn a cloudy or milky white, which indicates that the psychoactive compound tetrahydrocannabinol (THC) is at its highest concentration. Harvesting when the majority of trichomes are cloudy yields the most energetic and euphoric effects.
Waiting slightly longer causes the trichomes to turn an amber color, a sign that THC has begun to degrade into the more sedative cannabinoid, cannabinol (CBN). A harvest with a higher percentage of amber trichomes produces a more relaxing and body-focused effect. A secondary visual cue is the color change of the pistils, the hair-like strands on the buds, which darken from white to orange, red, or brown as the plant nears maturity.
Physical Removal and Initial Trimming
Once the optimal harvest window is determined, the plant is physically removed from its growing medium, typically by cutting the main stem at the base or separating the individual branches. The next immediate step is trimming, which involves removing the excess fan leaves and smaller sugar leaves that surround the buds. This preparation is done using one of two primary methods: wet trimming or dry trimming.
Wet trimming involves removing the leaves immediately after the plant is cut down, while the material is still moist and pliable. This method is often preferred in humid environments because removing the leaves speeds up the drying process, reducing the risk of mold formation. Wet trimming also takes up less space during the initial drying phase since the buds are smaller and more compact.
Dry trimming is performed after the plant material has been dried, with whole branches or plants hung up initially with the leaves still attached. The surrounding leaves help to slow down the drying process, which retains volatile terpenes and leads to a smoother final product. While dry trimming can be less messy since the resin is not as sticky, it requires a larger drying space and the brittle, dried leaves must be handled carefully to avoid dislodging the trichomes.
The Drying Process
The drying process follows trimming, designed to reduce the moisture content of the flower from approximately 75–80% down to a target range of 10–15%. This slow, even reduction of moisture is performed in a dark, well-ventilated space to prevent the degradation of cannabinoids and terpenes from light exposure and preserve final quality.
Maintaining precise environmental conditions is necessary, with the ideal temperature kept between 60–70°F (15–21°C) and the relative humidity between 45–55%. Temperatures above this range can cause the delicate terpenes to evaporate prematurely, while humidity that is too high increases the risk of mold and mildew development. Consistent air exchange is necessary to remove evaporating moisture, but fans should not blow directly onto the material, which causes uneven and excessively fast drying.
The drying phase typically takes between five days and two weeks, depending on the density of the buds and the environmental conditions. Growers use a simple physical test, known as the “snap test,” to determine when the material is sufficiently dry. A small stem should snap cleanly rather than just bend, indicating that the moisture level is low enough to safely proceed to the curing stage.
Curing and Long-Term Storage
Curing is the final refinement of the flower that follows the drying phase. This process is not about moisture removal, but about enhancing the smoothness, flavor, and aroma of the final product. Curing is performed by placing the dried, trimmed buds into airtight containers, most commonly glass jars, filling them about 70–75% full.
The sealed environment allows the remaining residual moisture from the center of the buds to evenly redistribute throughout the material. During this time, the breakdown of remaining chlorophyll occurs, which is responsible for the harsh, “grassy” taste often associated with freshly dried flower. This enzymatic process allows the true flavor profile of the terpenes to emerge.
The practice during curing is “burping,” which involves opening the containers once or twice daily for a few minutes, especially during the first two weeks. Burping releases built-up moisture and gases, such as ethylene and carbon dioxide, while introducing fresh air to prevent the growth of anaerobic bacteria and mold. Once curing is complete, which can take several weeks or months, the material should be stored in a cool, dark environment to maintain its quality over the long term.