Do you Need a Dark Period Before Harvesting Cannabis?

The percentage of cannabinoids and other constituent components in cannabis buds determines the quality of the buds, and gardeners go to great lengths to increase their levels. This also applies to the aromatic compounds known as terpenes. The extended dark period before harvest is a popular method for high-quality buds, ranging from 24 hours to a week or more. And don’t think that the effectiveness of darkness before harvest is a myth. It’s not like there’s only some weak anecdotal evidence to back it up. There are some compelling theories as to why this occurs.

An overview of the dark time before harvest

Aside from the major milestones in the cannabis plant’s life cycle, like the seedling, vegetative, and blooming phases, the plants also go through regular cycles relating to respiration, photosynthesis, and other metabolic activities. Terpenes and cannabinoids, the two most valuable active chemicals in the cannabis plant, a peak near the conclusion of the dark cycle and begin to decline as the light cycle proceeds. So, right before the sun rises, or when your grow lights turn on, is widely regarded as the optimal time of day to cut the plants down to optimize the terpene and cannabinoid content of your buds.

Common dark period before harvest theories

Here are prevalent theories explaining the dark time before harvesting your cannabis;

1. One explanation why dark before harvest improves cannabis quality is that mild stress increases resin production in buds. Lowering the nighttime air temperature is another method to stress your plants in a (supposedly) beneficial way. Alternatively, you can cool the root zone by watering mature plants with ice-cold water. There could be some truth, so go ahead and try it.
2. According to another theory, such a reaction to prolonged darkness is an evolutionary mechanism. Here’s how it works: cannabis begins to flower as the nights grow longer and longer. This tells the plants to act quickly to produce seeds before winter. Unpollinated female plants continue to have more flowers in the hope that some will catch pollen.

If the nights are not only long but also appear endless, producing more flowers. Such a reaction could not have evolved because no one in nature turns off the sun for several days.

3. According to another theory, sugars and starches travel from the above-ground part of a plant to the root zone at night and are stored there for future use. Now, sugars and starches need to improve the quality of the smoke.

However, they make it harsh and the taste unpleasant. Farmers slowly dry and cure their buds for several weeks to remove these unwanted substances (and chlorophyll). Conversely, you can do the same with the long dark period before harvest. At least partly.

4. Finally, there is this explanation, which is very good science. The level of cannabinoids and other components’ concentrations are known to fluctuate. It peaks at the end of the dark period (night), after which cannabinoids are partially degraded by light during the day. Cannabinoids protect cannabis flowers from the damaging effects of UV radiation.

They are naturally depleted, and plants slowly replenish them at night. So, the obvious option is to harvest your cannabis before the lights are on inside or at dawn outside. Some growers use shorter days and longer nights (for example, an 11/13 flowering light cycle). It’s also said to make cannabis more resinous, but experts are not sure it is true.

Lab results on the dark period before harvest

Many websites and forums mention research allegedly conducted by the Stichting Institute of Medical Cannabis (SIMM). It was one of two approved sellers of medical cannabis in Holland until it went bankrupt within a year or two*, thanks to an American activist named James Burton. According to stories, Burton and his colleagues reportedly conducted an intriguing experiment. They harvested half of the plants normally while leaving the other half in the dark for 72 hours.

Furthermore, when they tested the finished dried product, they discovered that the cannabinoid level in some strains was up to 30% higher than in their usual harvest counterparts. CBD and CBN levels were constant.

Darkness time before harvest and terpenes levels

During the dark cycle, the content of aromatic compounds in buds rises. During the day, some of the terpenes evaporate when the air warms and occasionally becomes hot. For this reason alone, it’s critical to drop daily temperatures by a few degrees throughout flowering, especially closer to harvest. Keep in mind that terpenes and flavonoids do more than make the smoke smell and taste better.

They also have an effect on the character of the high, which is known as the entourage effect. A few dark days before harvest naturally, lead to a higher concentration of terpenes in buds. Farmers who have kept their plants in a fully dark room for 24h-48h or longer have reported how strong the smell becomes.

How long should cannabis be left in the dark before harvest?

Assume you’re not in a rush and can wait as long as it takes for buds to achieve their best quality. How much time is enough? At the absolute least, pick your buds at the conclusion of their final night (the last 12 hours of darkness), manicure them under low lighting, and dry and cure them in a dark area. It is much preferable to extend the dark period. A 24-hour night will make little difference that you will notice. It’s more like 36 or 48 hours.

Additionally, experiments have proven the effectiveness of 72 hours or three days. Some producers have related experiences about having to keep their plants in the dark for 4-5 days, occasionally a week or more. The nugs were often said to be fire, but prolonged periods of darkness rendered the buds less firm.

What to do before harvesting your buds

Watch out for mold and bud rot

Ensure the soil is dry before leaving the cannabis in the dark before harvesting. Watering your plant before turning out the lights is a terrible idea. For starters, lesser humidity equals greater cannabinoids. Second, keeping both the medium and the air dry reduces the likelihood of mold and bud rot. Because you can only monitor your plants for a few days, take all measures if you want your crop to be completely protected.

Curing and drying in the dark

Trimming a plant and hanging it upside down in a dark closet to dry does not imply that the plant is dead. It has no roots, yet it is still alive, and the chemical reactions within it slow but continue. So, the concept of employing prolonged darkness to boost the quality of buds also applies here. When drying and curing your buds, never expose them to direct light. Complete darkness isn’t required, although it wouldn’t hurt.

Autoflowers in the dark before harvest

Given the enormous popularity of autoflower strains, it’s no surprise that people keep wondering if they can give their autoflowers a dark time before harvest. You certainly can. All of the preceding principles apply to any cannabis plant, even autos.

Other tips for cannabis pre-harvest preparation

When it comes to harvesting your plants, the time of day is one vital factor. As the days countdown to harvest, here are some things you may do to prepare.

Monitor the color of the trichomes

While there are a variety of indicators, such as yellowing fan leaves and the size/shape of your flower buds, many growers rely on the appearance of the trichomes to determine the best harvest time. Trichomes will appear foggy or milky when terpene and cannabinoid levels are optimal. Clear-looking trichomes are most likely still immature, whereas amber trichomes indicate that the chemicals inside are beginning to break down.

Choose whether you’ll be wet or dry trimming

You must trim cannabis plants once they have been harvested. It is time to decide whether you want to wet trim (trim before drying) or dry trim (trim after drying) your buds. Both have advantages and cons, and preparing ahead of time is essential for ensuring a smooth harvest process.

Flushing before harvesting

It’s common practice to stop feeding your cannabis plants a week or two before harvest, a method known as “flushing.” Flushing forces the plant to consume both the residual nutrients in the growth media and the nutrients stored in the plant. Excess nutrients in the plant at harvest time might result in a harsh and bitter end product.

Prepare harvesting and drying equipment

Prepare and keep everything you’ll need for harvest near reach. Consider the space and gear you’ll need for drying and curing and the right cannabis harvesting tools.

Darkness aids in the replenishment of terpenes in cannabis plants. Terpenes evaporate during the day. So, the early morning is the best time to harvest. And by extending the night before harvest to at least two days, you can (arguably) obtain more flavorful and potent buds.