Harvest your Cannabis
Learn every step of the cannabis harvest and post-harvest process.
Harvest time might seem like the end of a long journey. Your buds have ripened, and now it’s time to smoke up, right? Unfortunately, you’ll have to hold your horses a while longer. There’s still plenty of work to be done. You’ll need to trim, dry, and cure your buds to ensure a silky smooth smoking experience. All of the work you put in now will enable you to eliminate harsh flavours and store your stash for long periods.
Harvest time isn’t as simple as plucking buds and placing them on a drying rack. There are nuances involved, and the more precise you are with your timing, the better. Harvesting your buds at different moments will result in differing THC levels, and curing them at the right humidity will have a large impact on mould resistance.
This guide will assist you through each step of the harvest process to ensure a healthy and potent stash.
WHEN IS THE RIGHT TIME TO HARVEST?
The first step in the harvest process involves removing flowers and branches from your plants. But when is the right time to do this? Well, it depends. Harvesting at different times will drastically alter the characteristics of your flowers. Everything from taste to psychoactive effect can be modulated depending on how early or late you choose to harvest.
In general, every strain has its own estimated flowering time. This statistic can be useful in preparing for harvest, but it’s not always accurate. Environmental factors can extend or shorten the blooming phase. Indica strains mature faster and will flower for 6–8 weeks, whereas their sativa counterparts typically take 8–12 weeks.
There’s another way to detect when harvest is closing in. Some basic knowledge of plant anatomy can help growers spot these shifts. Certain parts of the cannabis plant begin to change in appearance as they ripen. Rather than relying on guesswork alone, you can use these botanical landmarks as indicators. First, you’ll need to get familiar with certain tissues, glands, and organs, so you know what to look out for.
FAN LEAVES WILL START TO YELLOW
Yellow leaves are usually a sign of nutritional deficiency or the presence of a pathogen. However, they are perfectly normal during the end of flowering. Fan leaves are the large, broad leaves that emerge during the vegetative phase. These organic solar panels work to convert light into sugars required for energy. These structures will begin to turn yellow and may even drop off when harvest time is approaching. Don’t be alarmed. This happens because plants are disregarding these tissues to divert as much energy as possible toward the flowers.
TRICHOMES BEGIN TO CHANGE IN APPEARANCE
Trichomes are the tiny, mushroom-shaped glands that can be seen shimmering on sugar leaves and flowers. These small chemical factories churn out cannabinoids and terpenes in the form of a viscous resin. In nature, these substances protect plants against heat, predators, and pests. But to growers, this resin is the primary reason for cultivating weed.
Monitoring trichomes is an accurate way to detect how close your flowers are to becoming fully ripe. Doing so will also give growers the freedom to harvest flowers at a time that suits their individual preference.
Trichomes are apparent to the naked eye, but you’ll need to use a magnifying device to properly analyse them. A cheap magnifying glass will do the trick, and is the tool of choice for many budget growers. Green-fingered photographers can take a snapshot with a macro lens. This will also enable them to track colour change over time. Commercial growers and those with more cash to spare can opt for a microscope. These lab-grade devices offer an extremely detailed view of trichome structure and colour.
Trichomes appear clear and translucent during the early stage of flowering. This indicates that they are still young and will only be producing low levels of cannabinoids. Flowers will also be physically smaller—an obvious sign that it’s not yet time to harvest
Later down the line, these glands begin to become more cloudy or milky in colour. This change in complexion signifies increased cannabinoid production. Keep a close eye on these structures as this milky colour begins to dominate. Trichomes will reach maximum THC production when over half of the glands have become cloudy. Buds harvested during this time will provide a potent head high defined by euphoria and increased energy.
If you prefer a more mellow and sedating experience when you smoke, wait for the trichomes to display an amber colour. This indicates decreased levels of THC and increased amounts of CBN, a cannabinoid produced as THC degrades.
CALYXES BECOME PLUMP
A calyx is the first part of a cannabis flower to emerge from the node. This structure starts off life as a bundle of small leaves and eventually unfolds into fully formed flowers. They remain at the base of each bud and house the reproductive organs. Calyxes are the most resin-rich part of a cannabis flower, and their role is to provide structural support, ensuring buds aren’t blown away during high winds or pecked off by winged predators.
Calyxes begin to swell as buds near maturation. This is because they are preparing to hold seeds if they are successfully pollinated by a male plant. Routinely hover your magnifying tool over calyxes to track their size.
PISTILS DEVELOP A DARKER COLOUR
Pistils, or stigmas, are the antenna-like sex organs that protrude from calyxes. These structures are tasked with capturing pollen released from male plants. They are the gateway to fertilisation, and females will begin producing seeds when their mission is accomplished.
Most growers strive to avoid fertilisation in order to produce high-quality flowers. However, pistils still come in handy as a marker of maturity. Young flowers feature bright white pistils that slowly darken with age, and then display an orange-brown colour. THC production is usually at its peak when around 70% of pistils have shifted colour. When approximately 90% have turned dark, THC levels will drop and CBN levels will rise. Do keep in mind, however, that these figures are just estimates.
TRY A PROGRESSIVE HARVEST WHEN LOWER BUDS AREN'T FULLY RIPE
If the flowers near the canopy have a significant number of cloudy and amber trichomes indicating they are ripe and ready for harvest, but crystals on the lower buds are still perfectly clear and far from ready, you can use a technique called progressive harvesting to ensure every bit of weed you chop is perfectly mature.
Also called a partial harvest or staggered harvest, this method is so simple, you'll be surprised that you didn't think of it on your own. Simply clip off the individual buds that are ready, trim back the remaining branches and leaves as needed to expose less mature flowers to more light, and watch for signs that they're ready to pick.
Most indoor plants only require two cycles of progressive harvesting set about two weeks apart, but larger ones may need more.
Note that most plants mature from the top down because the canopy gets the most light, and more lumens usually equals faster ripening. However, every plant is an individual, and you may find a peculiar phenotype that matures from the bottom up. And, some plants mature evenly from top to bottom, so they're not candidates for progressive harvesting.
IT’S TIME TO TRIM YOUR FLOWERS
Trimming, or manicuring, is the next step. It’s a necessary process to neaten buds up and to prevent sugar leaves from overrunning your stash jars. All you need for this task is a worktop, a tray, some latex gloves, and a pair of scissors. There are two ways to trim your harvest: wet trimming and dry trimming.
Wet trimming refers to manicuring your flowers immediately after harvest when the moisture content is still high. This decreases the chance of mould formation because all of the sugar leaves are removed before drying, preventing moisture from becoming trapped. The downside is that it’s a very sticky process. Gloves are a must. But there’s a silver lining; you can make scissor hash out of the resin that glues itself to your trimming tool.
Dry trimming involves manicuring your flowers after they’ve been dried. This method is better for when you’re dealing with a low humidity environment and less chance of mould. Dry trimming also results in buds being more tight and compact, an aesthetic that many growers value.
Regardless of what method you opt for, the task is still the same. You have the choice of trimming off sugar leaves whilst buds are still attached to branches, or you can remove individual buds and clean them up separately. Be sure to keep your sugar leaves, as they can be used to make hash and other extracts.
DRY YOUR BUDS
The next port of call is to get your bounty into the drying room. Drying cannabis is essential to removing moisture from the exterior of buds to prevent mould formation. Plus, smoking wet weed isn’t pleasant. Before you begin drying, dedicate a space to your operation. This can be a spare room or even the grow tent you used to cultivate. If you’ve left your flowers on branches, then you’ll need to set up a washing line to hang them from. Otherwise, simply place your buds on a drying rack.
For optimal results, cannabis should be dried slowly. It might seem easier to blast your buds in the oven, but this will only reduce the taste. Terpenes, the chemicals that give cannabis its flavour, are volatile and degrade at high temperatures. To initiate drying, you’ll need to achieve a room temperature of approximately 21°C and a relative humidity of 50%. Place a hygrometer in your drying space to measure both of these factors. If your readings are too high, use fans, air conditioning, and a dehumidifier. If they’re too low, install a heater and humidifier.
Drying usually takes between 2–7 days. Monitor your flowers closely each day and touch them to judge moisture levels. Eventually, stems and flowers should snap under force instead of bend. When this occurs, it’s time for the next step.
CURE YOUR CANNABIS FOR SMOOTHNESS
Have you ever smoked some dank-looking weed only to find it tears your throat apart? This is the result of uncured cannabis. Curing adds significant time to the end of the growing process, but it adds so much value to a harvest. It’s a prolonged drying process that removes moisture from the interior of flowers, something that drying alone cannot achieve.
Curing will enhance the flavour of your harvest and gift it with a smooth, pleasant smoke. It does this by breaking down molecules like chlorophyll that irritate the respiratory tract.
Curing will also increase the potency of your harvest. Before buds are heated during smoking, vaporization, and cooking, THC exists as THCA. This cannabinoid acid is broken down (decarboxylated) into THC under high temperatures, or with time. Curing encourages this process and slowly increases THC levels.
It’s pretty much a set-and-forget process. All you need are a few mason jars—enough to contain your entire harvest.
Load up each jar loosely to around 75% capacity, seal them closed, and store them in a cool, dark place. At first, the remaining moisture will move out from the inside of the buds, making your stash appear rehydrated. By opening the jars for a few minutes several times a day—a process known as burping—you’ll release this moisture and allow for fresh air exchange. Repeat this process during the first week.
During weeks two and three, you’ll only have to open your jars once a day for a few minutes as the moisture content decreases. After three weeks, your flowers will be sufficiently cured and will provide a smooth smoking experience. Some growers with considerable patience opt to increase the curing period for up to eight weeks to maximise flavour and potency. If you’re planning on long-term storage, know that you can cure your cannabis for over six months without harming your stash.