When it comes to growing cannabis, harvesting is like the eighth inning of a hard-fought baseball game, while the ninth inning is drying, curing and storing your crops. And as in baseball, unforced errors and rookie mistakes in either of these final innings can cost you the winning game.
Most growers have made at least one of these harvesting mistakes and paid dearly for their blunders. Let’s take a look now at the most common cannabis harvesting gaffes so you can avoid them and have a perfect finish to your growing game.
1.Relying Only On Bloom-Phase Duration Estimates
The majority of cannabis growers rely on bloom-phase duration estimates provided by seed breeders to determine when to harvest. If the breeder says bloom phase lasts 65 days, then the grower waits exactly 65 days in bloom phase before harvesting. However, cannabis is a plant, not a machine whose performance can be predicted with generic specificity. I’ve seen bloom phase durations that were as much as plus or minus 15 days from what the seed breeder recommended.
Many factors influence the length of bloom phase and optimum harvest timing, including:
- Plant phenotypes, which can vary even among clones and high-quality seed-grown cannabis plants.
- Environmental conditions.
- Whether pests and diseases have attacked the plants and to what extent, if any, those attackers were defeated by the grower.
- The quality and implementation of the feed program.
- The quality, intensity, height and placement of grow lights.
- The type of grow environment, e.g., deep water culture, soil, soilless mix, rockwool, coco coir and aeroponics.
- What cannabinoid and terpenoid mix and percentages the grower wants from their buds.
- The grower’s desire for the heaviest harvest possible versus harvesting at peak potency.
The Fix: Use seed breeder bloom-phase estimates only as a generic approximation, not as the final word on when to harvest.
2. Inadequate Monitoring Of Resin Glands
Cannabis resin glands are a plant’s version of a golf ball on top of a tee. The round glandular head (i.e., the golf ball) is where most of the cannabinoids, terpenoids and flavonoids are produced and stored, although some resins are found in the gland stalk (i.e., the tee) and in bud leaf material.
When resin glands are at their peak bloom, stalks are sturdy and vertical, while glands are round and clear.
Depending on strain genetics and varying degrees, resin glands go cloudy and/or amber as peak bloom phase advances. But as flowering expires and harvest time draws near, resin glands begin to fall off the stalks, while some stalks bend and topple.
When more than 25–35 percent of the glands are cloudy or amber, or when more than 25–35 percent of glands have fallen off the stalks or the stalks are bent or collapsed, peak resin potency has passed and the buds must be harvested.
The Fix: Starting in peak bloom, use a magnifying device to examine the resin glands that are several inches below the topmost canopy of your plants. In almost all cases, resin gland condition is the single most important indicator of peak potency harvest timing, with the breeder’s bloom-phase estimate a distant second.
3. Harvesting Too Early
When fed and properly lit, some cannabis strains gain 30–45 percent of their bud weight during the final third period of bloom phase, whereas for some late-gainer strains, buds can nearly double in size when fed a late-phase bud ripener during that same final third period of bloom. The bottom line is, if you harvest too early, you miss out on that weight gain, which means missing out on potentially 30–45 percent of your profits.
Harvesting cannabis too early also means that a significant percentage of cannabinoid, terpenoid and flavonoid production is lost. But it’s not just that the heads of resin glands have less time to swell up — it’s also that the compounds inside have less time to fully mature and ripen.
A strain harvested at optimum potency of 63 days in bloom phase may test out at 23.5 percent THC, but the same strain harvested too early may test out at 19 percent THC.
The Fix: Harvesting too early creates a different psychoactive experience. If you’re a trichome farmer who is focused on producing resin glands to make dry sift, bubble hash, kief or processed cannabis concentrates, harvesting too early robs you of some of your resin gland harvest. During late bloom phase, feed your plants Overdrive to boost bud growth and overall vigor.
4. Harvesting Too Late
If a grower isn’t paying attention to the color of resin glands and to structural integrity, or is waiting for the breeder’s suggested bloom-phase duration, then the crop can become overripe. The resin glands degrade, so a percentage is lost to decay and desiccation. Also, the ratios and percentages of cannabinoids, terpenoids and flavonoids change as the crop becomes overripe.
A strain harvested at peak potency that tests out at 23.5 percent THC and less than 1 percent cannabidiol (CBD) and cannabinol (CBN) may test out at 20 percent THC and more than 1 percent CBD and CBN when harvested seven days past peak potency. This cannabinoid shift changes the character and intensity of the high, and usually not for the better.
The Fix: While most of the bud weight will come at the end of the grow season, right before you harvest, always remember that timing is everything. Take care to carefully monitor your crop, especially trichome development, and if growing outside, also pay attention to the weather. This will involve getting in sync with the rhythm of the bloom-phase period.
5. Not Analyzing Psychoactive Or Medicinal Growing Goals
The timing of your marijuana harvest determines the intensity and type of medical and recreational effects your buds impart.
Harvesting too early, when all the resin glands are intact, sturdy and clear, provides a lighter, less intense, more stimulating high than harvesting at peak potency when some of the resin glands are cloudy and/or amber.
Harvesting too late, when many of the resin glands are cloudy and/or amber and a significant number of glands are degraded, produces a heavier, couchlock, numbing high.
You can get different types of recreational and medicinal effects from the same plant, depending on whether you harvest early, at peak potency, or too late.
The Fix: So, have you ever sat down and thought about exactly what kind of high you want from the cannabis you’re growing? Most growers haven’t. They grow their plants, harvest when they think the time is right, and accept whatever high they get. Now you know you have a choice — harvest early for a speedier high, harvest late for a heavier high.
6. Unsanitary Harvesting Procedures And Tools
When growing, cannabis can be attacked by such garden invaders as spider mites, aphids, thrips, powdery mildew and gray mold, and many growers will try to defend their crops against these pests during grow and bloom phase.
But those same growers let their guard down during harvesting, and that’s a mistake.
The Fix: The lack of hygienic practices and cleanliness can transfer pests and diseases from one plant to another, creating an epidemic that damages the drying crop that still has plenty of moisture left in it to support insects, molds or fungi. When harvesting many plants, frequently dip your pruners and trimming scissors in alcohol to sterilize them as harvesting continues.
7. Harvesting Without An Adequate Drying Site
Outdoor growers may find it difficult to keep to an optimum harvesting schedule because bad weather, disease, pests, wildfires, police and rippers can arrive suddenly and without warning, and force a harvest on the unsuspecting grower.
Growers who choose to cultivate outdoors often rely on a drying shed or barn, similar to what tobacco farmers use to hang their harvest for drying and curing. But bad weather or invaders could render this setup impossible.
Whether you grow outdoors or indoors, you need a climate-controlled, vented, odor-filtered room with the proper physical structures for hanging whole plants and drying racks for cut branches and buds.
The room should have optimum temperature, humidity and air movement to allow for steady moisture removal from buds.
Some growers, who harvest before their dedicated drying site is ready, will pile plants on top of each other, cut the buds off the branches, and throw them in bags, or hang the plants from clothes lines in humid rooms with poor air circulation.
All of these conditions degrade buds and can lead to mold infestation.
The Fix: In a scenario where no optimum drying site can be found, it’s best to trim buds from branches, bag them, and flash freeze them in deep, secure freezers.
8. Harvesting Without Enough Time And Personnel
Marijuana harvesting takes time. However, it can take very little time if all you do is cut the main stalk at the base of each plant and hang the plant in a drying room. If you intend to prune branches or buds during harvesting instead of just hanging the whole plant, then harvest time and energy is greatly expanded.
Cultivators who run large indoor or outdoor grow ops might not want to handle the entire harvest themselves. When roping in friends, associates or trimmigrants, this creates a security risk.
Most of the time, those helpers want to be paid, which will eat into your profits. And sometimes, those helpers steal part of the crop as they harvest it.
The Fix: Take the time to analyze how much manpower you’ll need to do your harvesting, and plan ahead accordingly. I’m glad to spend three hard workdays harvesting all my plants myself, rather than have an outsider know I’m growing weed.