Harvest

when is a cannabis plant ready to harvest?

It can be tricky determining when best to harvest your marijuana plant. Harvest too soon and the buds will not be potent enough and have smaller amounts of THC and CBD (the good stuff), harvest too late and the buds will be too potent and could create a sleepy effect.

A general rule of thumb for when the buds are ready for harvest is when the white pistils have darkened or turned a red colour and have curled back into the plant. The resin on the buds will become darker and start to brown in colour. The stem will also get wider and you may notice the leaves starting to turn yellow.

It is also a good idea to take a closer look at the trichomes under a microscope (these are the small hair-like outgrowths). They will initially start as clear and transparent and then turn to a milky white colour. You can harvest when it gets to this stage for a ‘higher’ or uplifting effect (the levels of THC are at their highest). Waiting a couple more weeks for the trichomes to turn an amber colour will produce a more relaxed effect (this will have slightly lower levels of THC).

Just before you harvest (around 1 to 2 weeks before), it is a good idea to ‘flush’ your cannabis plants. The flushing technique is used to get rid of any salt or nutrient residue in the plant. This involves running clean water through your soil or hydro system and improves the quality of your buds. 

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Licence GFDL
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Trichomes on the cannabis plant

checking harvest time by inspecting the pistils

One way to check whether your cannabis plant is ready to harvest is by looking at the pistils. This may not as reliable as checking the trichomes, but it is easy to do just by looking at the plant. The pistils will change from a white colour to a red or brown shade. There are various time frames here, where you could harvest, and each will have a different effect.

Once 50-75% of the pistils have browned, you could harvest but the taste will be slightly weak. When 70-90% of the pistils are a red/ brown colour, this is a great time to harvest as the THC levels will be at their highest. When 90-100% of the pistils have turned brown, you will not want to wait any longer. This will produce a heavy but calming effect. 

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Pistils turning amber colour

check harvest using trichomes

Using trichomes is an accurate way to identify if your buds are ready to harvest. As mentioned above, trichomes are tiny hair-like glands that live on the buds and are better viewed through a microscope. They appear as a white, frost-like sprinkling over the plant and will gradually change colour once ready to harvest.

If you look closely at the trichomes, you will see they have a small ball at the top of them. These are the trichomes that hold THC and other cannabinoids, as well as being the most potent part of the plant.

Looking closely through a microscope, if the trichomes appear clear or transparent, then they are not yet ready to harvest. When they change to a milky white colour, this is when they are at their highest level of THC and CBD. This is a good stage to harvest. If you are looking for less of a ‘high’ effect and a more relaxing feel, then wait a little linger until they turn an amber colour. 

how to harvest your marijuana plant indoors

After removing the grow lights, you will need to hang wires from the ceiling. You will need a good quality pair of shears, gloves to stop the sticky resin getting on your hands and alcohol to wipe off any resin from your equipment.

It is a good idea to remove some of the larger leaves before you start. You will then cut each branch of your plant at the base, and hand it upside down, attached to the wires. Be very careful when handling the plant so the trichomes do not fall off. Keeping the temperature around 17-18 degrees Celsius and the humidity at 45% (with an extractor fan running), place a fan below your upside-down plant, to increase the air circulation. The room must be kept dark. 

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Cannabis buds drying - (CC BY 2.0)

harvesting outdoors

It is possible to harvest outdoors although this is best in a warm climate. A warm and dry Autumn day is best (this is the beginning of October in the Northern hemisphere or early April in the Southern hemisphere). You can harvest in the rain without too many issues (it will just add a little into the drying time), but the plant will not like very cool or frosty weather. 

Marijuana Drying
Marijuana Drying Outdoors - (CC BY-SA 3.0)