Whether it’s once a year or once a week, harvesting a new crop of cannabis is among the most exciting and risk-laden tasks for commercial producers. Even the most experienced farmers can fall prey to simple and costly mistakes. The following is a list of eight common mistakes newcomers and veterans alike should look out for during the final stages of production.
1. Poorly planned pruning
Pruning cannabis is relatively simple process intended to allow for better light penetration and better air circulation near the middle of the plants. It’s easy to get overzealous while pruning and growers should aim to remove no more than one-third of the plant’s leaves and branches, prioritizing closely overlapping leaves and branches near the bottom of the plant. Over-pruning can put a plant into shock, which can lead early flowering and a diminished yield.
Topping plants should be done after the plant has at least three nodes and before it has six; too early can stunt development, while too late can damage the plant’s health. Similar pruning methods, such as lollipopping and fimming, should be done before the flowering phase.
In flowering, pruning should be limited to only removing dead, damaged or diseased leaves from the plant, or in rare cases to remove a fan leaf that is blocking light from a developing flower area — which, in theory, should have been done in veg.
2. Relying on bloom and harvest estimates
It’s important to keep in mind that bloom and harvest estimates from nurseries, breeders or fellow producers are based on their data, meaning it was collected from their medium, feeding regimen, lighting, etc. Depending on the difference in cultivation styles, bloom and harvest data can be off by weeks. Therefore, estimates should be used as a rough idea of the production timeline. Most growers give new genetics a long trial period before putting them into mass production, and even then, the estimate could be off if the crops faced an unforeseen event such as a change in feeding, a pest or disease outbreak, or even minor changes to environmental conditions or lighting.
3. Failing to watch trichome growth
Cannabis trichomes are more than just bud-porn fodder; they store a massive amount of cannabinoids, flavonoids and terpenoids. Trichomes are the best indicator of when a plant is at peak bloom, but the amount of time growers like to let them ripen varies wildly. As trichomes ripen they transition from clear, to cloudy, to an amber color. Some growers like to wait for about 20% of trichomes to have amber heads, while others say they wait for an even split between milky and amber. The one thing to keep in mind is that as trichome heads turn amber they begin to fall off and that’s bad. Waiting too long can bring down the overall potency of a harvest dramatically and harvesting too early can do the same. The best course of action is to examine the trichomes on numerous plants in the grow with 30-100x handheld microscope or a magnifying glass to get a consensus of where the crop as a whole is and then plan your harvest time.
4. Hasty harvesting
Trichomes aren’t the only thing growers can lose by harvesting early as many strains will put on a significant amount of weight during the final weeks of flowering. Some grower accounts state that specific strains may develop anywhere from 20-45% of harvestable flower during its final weeks, though the claims are often paired with feeding the plants a late-phase ripening concoction. Growers typically harvest early because of an upcoming deadline or fear of mold or rot forming on the plants. While growers may be employing any number of cultivation methods to trick the plants into flowering early, that doesn’t always translate to an earlier harvest. The trichomes, and to a lesser extent the pistils and stigmas, are the best indicators of when to harvest.
Ultimately, harvesting early is akin to taking a loss in terms of value, weight and potency so it literally pays to push the schedule out if possible.
5. Mishandling the flower
During the actual harvest and trimming, whether it’s wet or dry, by hand or by machine, there is going to be trichome loss. Those delicate white crystals that are so vital to the crop’s value are in fact delicate hairs and they can fall off as easily as a Christmas tree’s pine needles on January 2.
Growers can minimize trichome loss by developing a plan to move the plants through the final stages of production with as little contact as possible. Again, there are acceptable losses when it comes to trimming, but needlessly moving the plants multiple times is ultimately going to hurt the company’s bottom line and its reputation.
6. Failing to quarantine harvested plants
Cannabis growers go to great lengths to protect their crops from the multitudes of natural pests during the veg and flowering phases, and the same effort needs to be applied to freshly harvested plants. One of the biggest mistakes a grower can make post-harvest is to think the threat of mold or pests is past. Ideally, the plants would immediately be transferred to the next stage of harvest whether it’s bucking, trimming or drying, but those areas should be safe, sterile environments. Plants that are ultimately going to be consumed should not be left out overnight simply because the shift is over.
Drying rooms and curing rooms need to provide the flower with the same sanctity as grow rooms. Flower needs to be protected before and after trimming and at every step until it leaves the facility and goes onto store shelves or into the hands of a processor or distributor.
7. Lack of an assembly line
Ideally, producers should be able to trace a line across their facilities, starting where production begins and ending where products leave the operation — and it should make sense. Unfortunately, many operators enter the industry without the capital to build a facility from the ground up and are often relegated to whatever properly zoned location they can find and co-opt it into a cannabis grow. While that means the growing rooms are typically set in stone, the harvesting side of production — including the drying, curing, trimming and packaging segments of the operation — can be more flexible.
Operators should look at where product is shipped from in their facilities and trace it backward to packaging, to curing, to trimming, to drying and see where the assembly line can be streamlined.
8. Failing to capture (and learn from) harvest data
After all the flower is packaged, growers should have a wealth of information covering the costs of production and they should use it. In addition to the standard cost to produce versus value per pound, growers should review the costs for labor, the time invested in cutting, drying and trimming, the anomalies that occurred at the last minute, equipment wear and maintenance. More often than not, operators already have the data, they just need to analyze how the process could be streamlined.
Cannabis already has too many variables, so it can be easy to look at each harvest in a vacuum as if each crop is completely unique, and that may even be true to a certain degree, but the equipment, processes and direction is always in the hands of the operator.