Harvest Techniques
How do you like to trim your bud? Wet? Dry? By hand or with a machine trimmer? Today we’re discussing the cannabis harvesting process. How do you know your plants are nearing harvest time? One tell tale sign is to watch the pistil growth and color change over time. Pistils are plant organs and look like tiny hairs sprouting up alongside the bud and are nearly clear/white early on in the flowering cycle. As they near harvest time, you will see pistils start to darken and turn yellowish/orange/brown. When around 80% of the pistils have darkened, you’re ready to harvest. Another method to gauge harvest times is to use a jewelers loupe and watch the trichome heads closely - when they just begin to turn from crystal clear to cloudy or a bit milky, it’s time for the first step in harvesting: flushing.
The process of ‘flushing’ plants 1-2 weeks before harvesting is done by watering with pure water and no added nutrients in order to remove any accumulated or excess nutrients in the soil, forcing the plant to consume any build up of nutrients like nitrogen, potassium, and magnesium. Certain soil bases, like living soil, do not require flushing based on the constant stimulation and management of the soil food web, microbe activity, and healthy fungal activity.
After you’ve properly flushed your plants, the next step in the process is chopping down the plants and trimming them - or is it drying them? Different growers will use different techniques, and some will even use one technique or the other based on the cultivar. What’s the difference? Trimming is the process of removing the large fan leaves (the ubiquitous marijuana leaf) as well as the numerous sugar leaves that are found all over the bud and ultimately removing the buds from the branches. Wet trimming is when this process is sometimes done while the plants are still rooted in pots but is usually done immediately after they’ve been cut down. This has the benefit of making it easier to manicure buds, with fan and sugar leaves fully extended and ready for trimming. One major downside however is that this method often results in sticky shears that frequently need to be cleaned throughout the process. Wet trimming also decreases overall drying time as there is less plant matter to absorb excess moisture.
This brings us to drying and dry trimming. Once the plant has been harvested, it contains around 80% water by weight and needs to be dried to prevent excess moisture from causing mold or mildew. As it dries, it is still in many ways ‘living’ as numerous metabolic processes continue in the plant. In fact, the potency of cannabis continues to increase as it dries as CBGA molecules convert to THCA. Drying is accomplished through hanging the branches upside down in a temperature and humidity controlled room - in a room somewhere around 70 degrees and about 50% humidity for anywhere from 5-10 days, depending on the cultivar and growing conditions. Some growers prefer to trim their buds after this process is done. This is referred to as dry trimming. Dry trimming is extremely beneficial to in-tact trichome preservation. This is also beneficial because the fan and sugar leaves absorb water in such a way as to prevent buds from retaining too much moisture inside while being dry outside, for example.
Most every cultivator will tell you that trimming by hand is vastly superior to machine trimming. Machine trimming is primarily used by very large grow operations and is done by dumping roughly cut branches and buds into large machines with whirling blades that cut down buds into a uniform shape. While this may save time for big grows, it leads to many problems, including loss and degradation of trichomes as well as other valuable plant material. Furthermore, hand trimming is a unique opportunity for cultivators to examine each branch of each plant up close and identify any irregularities or issues that may impact quality, something that cannot be done by machine. Oftentimes, if you open a pack and all the bud looks nearly uniform in size and shape - almost football-like - it has likely been trimmed through a machine.
Finally, the cannabis is cured in airtight containers for a few days or weeks with new oxygen being added intermittently to allow the metabolic process to fully complete. The lack of oxygen and other nutrients leads many of the unnecessary compounds remaining within the plant, including sugars, nitrates, and minerals, to be metabolized for energy, leaving a more potent and pungent plant. After the curing process is complete, the cannabis will have lost around 95% of its initial water content but retains enough to stay fresh until used.
