Harvest Timing Can Significantly Increase Cannabis Potency

For cannabis producers, harvest day can feel like the finish line. The plants have reached maturity, the trichomes have been evaluated, and the next priority is getting the crop harvested and dried as efficiently as possible. However, emerging research suggests the story of cannabis quality is far from finished.

A 2026 study¹ published in the Journal of Applied Research on Medicinal and Aromatic Plants examined how harvest timing and industrial drying methods affected cannabis. What they found raises an intriguing question for cannabis producers: Could the timing of harvest have a greater influence on the final cannabinoid profile than the choice between common drying systems? The answer may have important implications for cultivators looking to improve potency, consistency, and postharvest efficiency. Let’s dive into what the study found and what it means for cannabis growers.

Harvest Timing Can Change Cannabis Potency

Cannabis potency is not necessarily fixed when the plant is harvested. In the study, outdoor-grown Cannabis sativa was harvested at two points separated by one week. Researchers then examined how that difference affected cannabinoid concentrations and the subsequent drying process.

The later harvested cannabis showed substantially greater accumulation of several cannabinoids. Total THC increased by 26.3%, while total CBG increased by 57.6%. Researchers also measured increases of 40.7% in THCA and 60.2% in CBGA in the later harvest. This is particularly interesting because THC and CBG were not the only compounds affected. Their acidic precursors also increased, suggesting that cannabinoid biosynthesis continued during the additional week before harvest.

This does not necessarily mean that every cannabis cultivar should automatically be harvested one week later. Cultivar genetics, environmental conditions, maturity, disease risk, and production goals all influence the ideal harvest window. Rather, the study demonstrates something more fundamental: that the final week of cultivation can materially affect the chemical composition of the crop.

Tray vs Hang Drying Cannabis to Reduce Moisture

Once cannabis is harvested, it must be dried to prevent microbial growth. The researchers evaluated two conventional industrial air-drying approaches, perforated tray drying and conventional hang drying. They were operated under controlled conditions ranging from 15–25°C and 40–60% relative humidity.

The study found that regardless of harvest timing or drying configuration, the cannabis followed a characteristic drying curve, with moisture declining rapidly at first before slowing as drying progressed. Overall, both tray and hang-dried cannabis reached the study’s recommended moisture threshold of 12% or less within six days.

Rain Can Affect Cannabis Drying Rates

Weather is another factor that affects cannabis. In the study, the second harvest had a higher initial moisture content because the plants had experienced rainfall before harvest. Rather than simply making drying slower, the higher starting moisture content significantly affected the early stages of the drying process. This is where the choice of drying configuration became important.

Perforated trays produced a higher drying rate than conventional hanging, with the difference particularly relevant for the wetter, rain-affected cannabis. These tray systems could provide an operational advantage when producers are dealing with cannabis entering the drying facility with elevated moisture.

This does not mean that hang drying is ineffective. Both systems successfully reduced moisture to 12% or less within six days under the controlled conditions. Instead, the results illustrate how drying configuration can influence processing speed, particularly when the incoming biomass has different moisture characteristics.

Humidity Sensors for Drying Cannabis

Knowing when cannabis is actually finished drying is more useful than simply knowing how long it has been in the drying room, however, this can be difficult to know. To help solve this problem, the researchers used strategically positioned relative-humidity sensors to monitor the drying environment in real time. Those measurements helped track drying progression and identify the endpoint, reducing reliance on subjective judgment and fixed drying schedules.

This could offer commercial producers a more responsive way to manage postharvest processing. Rather than relying exclusively on a predetermined number of days, operators can use real-time environmental data to better understand how the crop is behaving, which is especially important when harvest conditions vary.

Air Drying Can Increase THC and CBG

Drying does not simply remove water; it can also change cannabis chemistry. One of the study’s fascinating findings was evidence of partial decarboxylation during conventional air drying. The researchers observed this with both tray and hang drying. As a result, air-dried cannabis showed increased concentrations of THC and CBG while still retaining high levels of their acidic precursors.

This is an important consideration when interpreting cannabinoid testing, as changes in measured THC or CBG following drying can reflect both the plant’s biological development before harvest and chemical transformations occurring during postharvest processing.

How Air Drying Changes the of Cannabis

Researchers compared the conventionally air-dried cannabis with the same harvested material preserved through laboratory freeze drying, which served as a preservation reference. The results showed that both tray and hang-air-dried cannabis experienced greater degradation of color pigments than the freeze-dried reference material.

That does not necessarily make freeze-drying the practical answer for every commercial operation, as industrial facilities must consider equipment costs, throughput, energy requirements, and other production realities. But the comparison demonstrates that drying configuration can influence visual quality as well as moisture removal and cannabinoid chemistry.

What Cannabis Growers Can Learn From the Study

Perhaps the most important lesson from the research is that harvest timing and drying should not be viewed as completely separate decisions, as they are all inherently connected. Harvest timing influences the cannabinoid profile and initial moisture content of the plant, weather can further alter that moisture content, and drying configuration determines how efficiently that moisture is removed. Temperature and relative humidity also influence the drying environment, while real-time sensors can help determine when the process has reached its endpoint. Changing just one variable can greatly affect the others.

For cannabis growers, this creates an opportunity to approach postharvest processing as an integrated system rather than a series of disconnected decisions. Instead of asking only when to harvest or whether to hang or tray-dry, producers could consider how harvest maturity, incoming moisture, drying configuration, temperature, relative humidity and real-time monitoring work together.

Final Thoughts

Cannabis production has become increasingly data-driven, but harvest and drying decisions are still often treated as routine operational steps. This research suggests they deserve considerably more attention, as a one-week difference in harvest timing was associated with meaningful changes in cannabinoid accumulation. Additionally, the first six days of drying influenced moisture removal, cannabinoid conversion, and visual characteristics. For cannabis producers, that creates an opportunity to improve consistency by combining careful harvest planning with real-time humidity monitoring and an appropriate drying configuration.

The biggest takeaway is not that trays are better than hanging, or that harvesting later is always better. It is that cannabis quality is shaped across a continuum. The final week on the plant matters, just as the first days after harvest. And the interaction between those two stages may ultimately matter more than any single processing decision.

References:

^{1. Philip Wiredu Addo, Jonathan Béland, Mickael Rizzo, Michelle Carbonell, Nichole Taylor, Michelle Shearer, Sarah MacPherson, Vijaya Raghavan, Valérie Orsat and Mark Lefsrud, Industrial drying of cannabis (Cannabis sativa) using tray and hang air-drying systems, Journal of Applied Research on Medicinal and Aromatic Plants, (2026) doi:https://doi.org/10.1016/j.jarmap.2026.100736}