Traditionally, the time to harvest comes in the fall after the summer growing season has waned and before the cold of winter has arrived. When it comes to growing cannabis, however, you don’t necessarily need to be limited by the weather outside.
No matter what type of growing method you prefer, if you’re growing cannabis indoors, you don’t need to be restricted by the seasons. The only problem is that this situation raises a question: when should you harvest cannabis when growing it inside your home?
The answer usually comes down to the strain and your personal preference, so the best way to know for sure is to visit the friendly staff at the best hydroponic store in Bowmanville. They’re horticulturists who love supporting their customers through every stage of the growth journey.
To begin answering the question of when the best time is to harvest your cannabis, it’s helpful to look at what happens during the plant’s growing phase.
As Your Cannabis Plant Grows…
As the cannabis plant grows, the flowers cluster together to form ‘buds’ (known as kolas), and each ovary swells up, growing small crystals around the flowers.
As the plant matures, both the pistils (the ‘hair’ you see in a bud) and the trichomes (microscopic, mushroom-shaped resin glands) found on the flower change shape and colour. Pistils turn from white to reddish-brown, and the trichomes from clear to milky-white.
The resin produced by the trichomes contains THC, the psychoactive compound responsible for getting you high.
How to Know When Your Cannabis Plant is Ready for Harvesting
Different types of plants, called cultivars, show when they are ready to be harvested in different ways. Each has unique characteristics because of the unique chemicals they contain. These chemicals might appear earlier or later during the growth of different cultivars.
For example, certain types of sativa plants can take up to 16 weeks to flower, while indica plants can take as little as 5 weeks to ripen. It’s also important to note that the flowers of a cannabis plant don’t mature at the same rate. The ones at the top usually contain more trichomes (and therefore more THC resin) than flowers at the bottom of the plant because they get more light.
However, THC isn’t the only factor in a plant’s potency. Another well-known cannabinoid impacting a plant’s potency is cannabidiol (CBD), which isn’t intoxicating but can produce a calming effect and is used in therapeutic products. Both THC and CBD evolve from another cannabinoid known as cannabigerol (CBG).
The optimal levels of both THC and CBD are reached when CBG has been entirely converted during the plant’s growth. After that, both THC and CBD begin degradation, turning into the cannabinoid cannabinol (CBN).
Generally speaking, growers analyze the colours of the pistils and/or trichomes to help them decide when to harvest.
Methods for Choosing When to Harvest
As the plant matures, CBG converts to THC and CBD, causing both trichomes and pistils to change colour. Growers will often use a magnifying glass or a microscope to judge the percentage of each that has taken on a new hue and use it as an indication that the plant has reached its desired levels of THC and CBD.
Trichomes undergo a gradual colour change from clear to milky white as the plant matures. When trichomes become opaque and milky-coloured, it indicates that resin production has peaked and secondary metabolites like THC, CBD, and terpenes are present in maximum concentration. However, not all trichomes change colour at the same time, and some may turn amber or brown while others remain milky. For optimal results, some growers harvest their marijuana plants when over half of the trichomes have turned cloudy and milky while only a few have turned amber.
Pistils change colour from white to brown or orange as the plant approaches maturity. This change signifies a decline in the pistil’s biological functions of trying to receive pollen and producing seeds. Based on that change, some harvesters wait until around 70% of the pistils have turned brown or orange. The plant is past its prime if 90% of the pistils are brown or orange.
Finally, more scientifically-inclined growers use chemical testing equipment to monitor their crop’s cannabinoid concentrations. CBG levels are tracked, and when they approach zero, it signals that all of the CBG has been converted into THC and CBD, indicating it’s time for harvest.