With marijuana legalization in Canada already a month behind us, many people across the country are wondering how to grow marijuana at home. Most of you will know that the new laws mean you are now allowed to cultivate up to four plants in your own home for personal consumption. What many may not know is that growing high-quality weed involves a lot more than just getting your seed to sprout and caring for the plant. Knowing when to harvest cannabis is very much an important part of the equation if you’re planning to grow good weed.
There are many factors that go into successfully growing marijuana, and if we were to cover it all here we’d keep you reading for a week! In one of our previous articles, we covered the basics of growing cannabis. Let’s skip ahead to what’s often the more challenging part and focus instead on when to harvest cannabis as well as how to dry weed and the best ways of drying and curing marijuana.
How to Tell When to Harvest Cannabis
There are two primary methods for determining when to harvest cannabis – the pistil method and the trichome method. The pistil method is quite straightforward and can be conducted by even the most novice and unequipped of growers, while the trichome method is more detailed and will require you to have certain tools at your disposal.
Let’s have a look at them first, and then we’ll discuss drying marijuana and curing marijuana.
Pistils are the small and thin white hairs found sticking out from amongst the buds while they are growing. Following the pistil method of determining if your weed is ready for harvest is quite simple; if they are white and sticking out straight then it is too early to harvest them. You need to wait until the pistils darken and being to curl in. Harvesting at 60 to 70% darkened pistils will mean you get the highest levels of THC in your bud, and you should never harvest when the total number of darkened, curling pistils is less than 40%.
Waiting until you have a 70 – 90% count means you will have buds with more of a balance between THC and CBD, and this tends to be preferable for people who are growing for medicinal / therapeutic purposes. Discussing when to harvest cannabis should include noting that some strains will produce new pistils even as the older and more numerous pistils are indicating it’s time to harvest. You can ignore these, and harvest the buds. Note as well that some strains keep most of their pistils white even when they’re ready for harvest. They should still be curling inwards though.
We’re big fans of simplicity, so here’s a great tip – search online for pictures of what your strain should look like when it’s fully ripened and ready for buds to be picked.
The trichome is a much more reliable determination method when figuring out when to harvest cannabis. Trichomes are the mushroom-looking resin polyps on marijuana buds that make them so sticky. There are different trichomes on all buds, but you need to be focusing on the ones that have a tiny ball on the top of them. This is where the lion’s share of the cannabinoids is concentrated, including THC, CBD, and CBN. THC content is priority #1 for the majority of recreational growers, while CBD is usually the priority for medicinal users
Trichomes are extremely miniature, so it is best to have some way of magnifying them. A jeweler’s loupe is a good choice for those working with a budget, as they’re relatively inexpensive. A digital microscope is a better choice, and while they can be more expensive they do have a big advantage. You’re able to record footage for reviewing it more comfortably later with the larger screen of your computer or notebook.
The specifics of the trichomes method involves seeing how clear or ‘cloudy’ the trichomes are. If trichomes are clear, they haven’t developed many cannabinoid stores within them. Once trichomes start to become cloudy then you can know that they are starting to build up their cannabinoid levels.
Trichome method guidelines:
We’ll start here by saying that if the pistils don’t indicate readiness, you don’t need to concern yourself with observing trichomes. Once they do, follow these guidelines:
- When trichomes are half clear / half cloudy the buds are still growing. However, they can be harvested for marijuana that produces more of an upbeat, energetic, and ‘rush’ high.
- Buds are at or near maximum growth when the trichomes are mostly cloudy and 50 to 70% of the hairs have darkened. They can be harvested for a yield of crop that provides the most intense euphoric high, along with plenty of pain relief for anyone aiming to use medicinally. These buds will have the highest levels of THC, and typically fairly high levels of CBD and CBN as well.
- When trichomes become cloudy and start to have a slightly amber hue to them they are fully grown and have reached full maturity as well. 70 to 90% of the pistils will have darkened by this point too, and this bud will be more of an equal balance of CBD and THC with more CBN. It will provide a more narcotic and sedating high that is better for those using to improve relaxation, and many people say this weed gives them a nice ‘body high’.
Some sativa and haze strains have trichomes that never really turn amber, even after they’ve become plenty cloudy.
This is a fairly simple but reliable way of knowing when to harvest cannabis. Keep in mind that harvesting any type of bud especially late will mean it has more sedative and less psychoactive potential. Trichomes that start looking more solid grey rather than cloudy, or appear to be withering, are past their harvesting prime. The buds will often do little more than make you sleepy.
Learning how to dry weed is equally important. But why dry and cure anyways? Well, aside from the obvious need for a dry product to eventually smoke there are a number of other ways that drying marijuana and curing marijuana play roles in determining the quality of your yield. These include:
- Breaking down chlorophyll and improving taste / smoothness in a big way
- Eliminating fresh cut plant material smell
- Making inherent flavours and smells more pronounced
- Making it less ‘harsh’ so you don’t cough as much or get a headache from smoking it
- Reducing promotion of anxiety, paranoia, and ‘racing thoughts’
- Eliminating mold and bacteria more effectively
- Increasing potency
Buds are best dried at room temperature – around 21 degrees Celsius, and with 50% humidity. Growers will often adjust their environment with air conditioners, evaporative coolers, humidifiers or dehumidifiers, or heaters.
Allow your buds to dry slowly over 3 to 7 days, and a good way to test if they’re sufficiently dry is to try bend the stems from the stalk. If they snap off rather than bend then your bud is dry enough to move to curing it. One last note is never try to ‘quick dry’ your buds using a heat source. It will make them taste harsh and unpleasant.
Process of Drying Marijuana
- Hang buds with tops facing down and stems up. Alternately you can hang an entire plant upside down to dry
- Trim away fan leaves. Cut away more of them if you live in a humid climate, and fewer of them if you live in a drier area. More humidity means more chance of mould. A drying rack is good if you live in a humid area
- Don’t dry buds lying flat on any solid surface as it will create a moist spot on them
- Humid environments may benefit from an area fan to increase airflow, but make sure it’s not pointing directly at your hanging buds. Only use a fan if you must, and be careful not to over dry
- When the smallest of your buds snap off from the stalk, they’re ready for curing
Last up in our discussion of when to harvest cannabis is the process of curing marijuana. Curing well goes a long way to having buds that are perfect mix of flavour and potency. The most important factor for curing dried marijuana well is to control the humidity of the environment. However, do not measure for humidity anytime within the first 2 days of placing your buds in the jars. They need time to ‘sweat’ – eliminating moisture contained in the middle of the bud that needs to move outwards towards the exterior.
Once you’ve let them sweat for a couple of days, you can go ahead and measure. The ideal is around 60-65% humidity inside your containers, and most growers shell out the buck required to buy a hygrometer to take accurate reads of the humidity. General guidelines for humidity are as follows:
Wet (Determined or estimated to be 70% relative humidity) – place buds outside jar for half a day to a full day. Remove them immediately as continuing to let them rest against each other in this condition can promote mould growth.
Moist (Determined or estimated to be 65 to 70% relative humidity) – leave buds in jar with top off for 2-4 hours
Dry (Determined or estimated to be 60-65% relative humidity) – this is your ideal humidity for curing marijuana buds
Brittle (Determined or estimated to be 55% or less relative humidity) – too dry, curing is impractical but if you do want to cure them still you re-hydrate them with a humidipak. This is not necessary but very helpful if you are curing in an environment that is naturally very dry
Process of Curing Marijuana
- Placing dried bud into glass jars (ideally) with closed lids
- Open jars once a day for 30 minutes or so, good idea to move buds around during this time
- Check on them during this time to make sure no mold or bacteria are growing
- Smell of ammonia or outside of buds feel moist means buds are too wet. Leave lid off jar for an entire day and check again
- ‘Touch test’ – squeeze firmly between fingers, evaluating how moist the buds are
- Be aware though that rehydrating brings the risk of mold growth, and in particular if you use an orange peel. That’s a grower trick that’s been around for years but really isn’t advisable for this reason
Dry for anywhere from 2 weeks to 1 month as necessary.
We hope this guide is useful to determine when to harvest cannabis and how to dry and cure your herb!