You have worked hard over the past weeks! Maybe you have spend some money in a growing tent or in cannabis seeds ; after a long time and hard dedication, you have finally arrived at this crucial moment.
How to know when to harvest your marijuana plants?
We will see here which is the best moment to harvest your marijuana plants at their psychoactivity peak, and try to understand what happens in our plants during the last weeks of flowering. In this way, you will be able to harvest your plants depending on the desired effect.
The marijuana harvest window is an aspect that, unfortunately, is rarely taken seriously; other times, what happens is that the grower just don’t have enough patience to wait for a few days to ensure highest levels of THC.
Some cannabis strains are better when harvested at their THC production peak, while others will be better if harvested a few days later.
Regarding trichomes and what they tell us, Robert C. Clarke – in his book “Marijuana Botany” – states:
When resin trichomes are near their THC concentration peak, they have a translucent colour since the plant is still producing resin in the trichome glands.
At this moment, THC production is at its peak, while CBD levels are still low and stable, since molecules quickly become THC.
Terpene – aromatic molecules – production is also at its peak, developing gorgeously aromatic floral clusters.
Many growers harvest their cannabis plants at this moment because they prefer a more clear and cerebral psychoactive effect.
At this moment, THC has few sedative effects due to low CBD and CBN levels.
What does it all mean?
If you are growing mostly Indica hybrids, it is better to harvest your plants when the resin glands are completely developed but not fully ripen – before they turn amber – unless you want to be glued to your sofa.
The harvest time depends mostly on marijuana strains and phenotypes, and can vary from several days to a few weeks between different cannabis varieties.
If you extend too much the flowering period of an Indica strain, it will dramatically affect its taste and effect. Fortunately, extending only a few days the flowering stage don’t usually cause major issues for most people.
It is recommended to observe close-up shots taken with a HD digital camera; however, a small hand-held microscope is cheap and works greatly. It is almost like being in a worls of aliens when we observe our cannabis buds with a fifty magnification lens!
If growing mostly Sativa hybrids , make sure that all resin glands are fully developed and 30% of them are amber before harvesting your plants.
If you extend the flowering period, you take the risk of decreasing both the taste and the typicall sativa “high” – stimulant – effect. However, there are always exceptions: the Haze strain has 3 different harvesting times, all of them after a long flowering period. Each grower must learn what he and his patients understand as “high effect”.
We haven’t discussed the yields, since we understand that if your plants are at the third stage of flowering and have completely developed resin glands, then they will yield at their full potential.
While there will always be few variations, you can use the following rules to better identify the harvest window of your plants according to the ripening stage of their trichomes:
1) When the bulbous heads of the trichomes are fully developed but still translucent, plants will produce a “high” and stimulanting effect, less sedative. It is the perfect moment to harvest strong Indica strains.
2) When these bulbous heads turn milky is probably the best moment to harvest most available hybrids.
3) When 70% of these trichome heads are milky and 30% amber, it is the perfect time to harvest mostly Sativa hybrids and long flowering strains (like Haze). It is also the best moment to harvest plants for making hashish.
As an example, let’s see what happens with Jack’s Cleaner marijuana : if harvested after 56 days of flowering, all trichomes are translucent (only a few of them are turning milky). At this moment, the effect is very stimulating, “up and high”, clear. It produces visual effects and its acid citrus taste is very intense.
The same plant, harvested only a week later – 63 days of flowering – shows milky trichomes, and 30%-50% of them have already turned amber.
If harvested at this moment,the effect will be heavy and intense, and the acid citrus taste becomes sweeter, reminiscent of the sweet smell of fermented lemons, similar to Lemon Heads sweets. The effect is now body relaxing and sedative, being a perfect smoke for relaxing before going to spleep.
It is alsmost an example of plant harvested too late. However, in this way we take profit from all the medicinal properties that the plant has during this late stage.
Another example is Killer Queen. After 49 days of flowering, it has chocolate taste and smell and that mentioned high and stimulant effect . If harvested after 60 days of flowering, it becomes “Super” Killer Queen, with both a skunky smell and a more strong effect, almost hypnotic.
The main mistake here is harvesting your plants when thricomes are not fully developed; most growers who follow the aforementioned rules will probably harvest their plants with milky, completely developed trichome heads.
Harvesting too early means less potent buds, with less essential oils and terpenes, so your buds will taste like grass or hey, even when correctly dried and cured.
A good option is harvesting the more ripe buds – which are usually those from the upper parts of the plant -. This allows the lower parts of the plant to have more light, thus increasing both the final weight and density.
If you have a digital camera with Macro function, you can take close-up shots and use a photo-editing software to zoom the pictures and observe the trichomes.
These tips will help you to improve the results of your favourite marijuana varieties, as well as to set the appropiate harvest window of those strains that you are growing for the first time.