How to dry and cure cannabis
After cutting down marijuana plants at harvest, a proper dry and cure are crucial for buds. These processes help preserve and accentuate flavors by retaining terpenes and cannabinoids, while diminishing chlorophyll and getting rid of the vegetal taste of the plant.
The drying process is the initial drying of buds, which usually happens in the open air—freshly harvested plants can lose up to 75% of their weight to moisture loss, as well as sticks, stems, branches, and leaves that get trimmed off.
When dry trimming, drying happens first and then buds are trimmed; in wet trimming, vice versa.
A dry shouldn’t be too quick or too long: Too quick and the outside of buds will appear dry but the insides won’t be; too long and buds could develop mold.
When buds are trimmed and dried, they are placed in airtight containers for curing. This stops the loss of moisture, preserving flavors and aromas and allowing buds to take on their full flavor.
How long does it take to dry cannabis?
Drying takes about 2-7 days. The process is usually shorter when wet trimming because most of the plant material is trimmed away first and there is less plant to dry.
When dry trimming cannabis, you can hang harvested plants upside down on a line or hanger, either whole plants or branches—this prevents buds from getting flattened or misshapen as they dry.
When wet trimming, you’ll place trimmed buds on a drying rack.
Whether wet or dry trimming, check drying buds or branches after two days by bending a branch or stem—if the stem snaps, that means buds are fully dry. If they don’t snap, leave them and check the next day.
How to set up a cannabis drying room
Keep harvested weed in a dark room with temperatures between 60-70°F and humidity between 55-65%. A cheap hygrometer will help you monitor these numbers.
Add a small fan to circulate air, and you may need to add a dehumidifier or AC as well. If it’s taking too long to dry buds in your space, you may need to adjust the temperature or humidity to help the drying process.
Cannabis drying room equipment
- Drying rack or line to hang buds for drying
- Hygrometer to measure temperature and humidity
- AC unit (optional)
- Dehumidifier (optional)
How to dry buds without hanging on a line
When trimming wet, you’ll need a flat rack—you’ll have lots of trimmed individual buds, so you can’t hang them. Flat racks are circular with layers of mesh, and are great for airflow.
Check wet-trimmed buds drying in the flat rack after 2-3 days by giving them a little squish. If they’re still too wet, leave them and check again the next day.
How to cure marijuana
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
When buds are done drying and have been trimmed, the initial amount of moisture is out and it’s time to cure your weed.
For curing, you’ll be storing finished buds in containers—typically airtight glass jars—to stop the loss of moisture, and to preserve flavors and aromas. Curing usually takes two weeks to a month, and humidity inside curing containers needs to be between 55-65%.
Why curing cannabis is important
The curing process is possibly the most overlooked aspect of growing weed. During curing, moisture continues to draw from the center of the bud toward the outside.
Curing affects the flavor and quality of the smoke. Many terpenes, which give cannabis its unique smell and flavor, are quite sensitive and can degrade and evaporate at temperatures as low as 50°F. A slow cure at low temperatures will preserve terpenes better than a quick, hot dry.
A proper cure also allows you to store weed for long periods without worrying about mold or cannabinoid or terpene degradation. Well-cured flower can be stored in an airtight container in a cool, dark place for up to two years without significant loss of potency.
Equipment and tools needed to cure cannabis
When curing cannabis, it should be done in a room or space that has a stable temperature and humidity—dank, wet basements or hot, muggy attics aren’t ideal. The space should maintain room temperature and not be too humid.
Light can also degrade terpenes, so it’s ideal to be able to turn off the lights in the space or be able to cover jars so light doesn’t leak in.
To cure buds, you will need:
- Airtight jars
- Hygrometer (for each jar) to measure temperature and humidity
Curing cannabis buds
Once buds are dry, it’s time to cure them.
Place the trimmed buds into some type of airtight container. Most people use wide-mouth quart or half-gallon glass mason jars, but you can also use ceramic, metal, or wood vessels.
Plastic bags are unsuitable for curing as they are not impervious to oxygen. Also, you don’t want your weed tasting like plastic.
Pack buds loosely in containers without compacting or crushing them. Seal containers and store in a cool, dry, dark place.
Within a day or two you’ll notice buds get a little softer as moisture from the middle of the buds rehydrates the outer parts. If this doesn’t happen, you have likely over-dried your cannabis.
Humidity inside sealed jars should be 55-65%. If you’re unsure, you can also buy a digital hygrometer—which measures moisture—available for $20 or so at any hardware store.
If buds are too dry, you can add a humidity pack, such as a Boveda pack, to rehydrate buds.
If buds are too wet, leave the lid off for half a day or a full day before resealing them. Be sure to check humidity levels every day and leave the lid off for a period of time if they still are too wet.
Burp your buds
During the first week of curing, regardless of humidity level, open the containers once or twice a day for a couple minutes—this is called burping. This releases moisture and replenishes oxygen inside the container.
If you notice an odor of ammonia when opening a container, it means the buds are not dry enough and anaerobic bacteria are consuming them, which will lead to moldy, rotten cannabis. Leave the lid off for a day and reseal tomorrow.
After the first week, burp containers only once every few days.
How long does it take to cure cannabis?
After two to four weeks in containers, your cannabis should be cured enough to give you a flavorful, aromatic, and quality experience. Some people prefer to cure for four to eight weeks, and some strains even benefit from six months or more of curing.
How to store your harvested cannabis buds
After curing cannabis, you can store buds for up to two years without much loss of potency. Like fine wine or a whiskey barrel, properly dried and cured cannabis is best when kept in a cool, dark place—mildew and other molds on cannabis and organic matter thrive in temperatures between 77-86°F.
Excessive heat can dry out cannabinoids and terpenes that have taken months to develop. When these essential oils get too dry along with plant material, it can result in a hot, harsh smoke.
Here are some tips for storing buds:
- Store out of direct sunlight in a cool, dry place
- Store in containers with a neutral charge, like glass mason jars
- Use hygrometers or products like a Boveda pack to monitor and control humidity levels
- Vacuum seal jars and containers to minimize oxygen exposure
- Separate strains to maintain individual flavor profiles, and label with a date—it sucks to mix up strains
Lower temperatures also slow decarboxylation, the process in which THCA converts into the intoxicating THC. THC eventually degrades into CBN, a cannabinoid with different effects and properties. Additionally, warm air holds more moisture than cold air.
Humidity control is paramount to keeping mildew and other mold contaminants out of your cannabis. Keep cannabis between 55-65% relative humidity when stored to maintain and enhance color, consistency, aroma, and flavor.
Harmful UV rays break down many organic and synthetic materials, and UV rays will degrade cannabis over time. Storing cannabis out of direct light will also help control temperature.
Preserving Cannabis Genetics: How to Collect and Store Seeds and Pollen
Sometimes a grower has to move on from a certain strain. Maybe you’ve been growing the same strain for a long time and it no longer makes as much money as it used to, or maybe you just want to mix it up and start growing something else and don’t have the space for it.
It can be bittersweet saying goodbye to old genetics, but sometimes it’s unavoidable. You can take clones or keep a mother plant, but those aren’t ideal because they require a lot of care and maintenance, especially if they aren’t producing flower.
Fortunately, preserving genetics for long-term storage is easy and will save time, money, and space in the long run. Through seed and pollen collection, you can hang onto those genetics that you can’t fully get rid of and safely store them for future use.
The Benefits of Long-Term Storage
Cannabis genetics are often sourced from external companies and organizations such as nurseries and seed banks. For the individual grower, saving seeds and pollen removes this reliance on external companies. This is especially true with pollen, as very few (if any) companies offer pollen to the public.
Saving space is a big reason to consider long-term storage of seeds and pollen. Mother plants lay dormant in a vegetative state and take up lots of space. Maintaining this extra space is time-consuming and takes extra resources like water, soil, nutrients, light, and other costly elements, all for something that doesn’t produce flower. Even keeping clones of an old strain around will take up space and resources.
A grower or breeder can also freeze the progress of a breeding project for months or years without losing any of the long, hard work. Endeavors such as phenotype hunting and maintaining desired mothers for breeding and cloning can all be saved for later through genetic preservation. This process is like backing up work on a hard drive.
How to Collect Seeds
Cannabis is for the most part dioecious, meaning that the male and female reproductive organs exist on two separate plants (although hermaphroditic plants do occur). It is also a wind-pollinated plant, so pollen must be transferred from a male stamen to a female pistil via the air in order for pollination to occur and seeds to form.
A female cannabis plant that has received pollen from a male will produce many seeds over the course of its maturation cycle. Upon senescence, when the female plant is fully mature and ready for harvest, its seeds will be ready for stratification and collection.
To collect seeds, it’s important to wait until they are fully mature and ready for harvest. Cannabis with seeds takes longer to mature than cannabis that only produces flower.
To tell if a seed is mature, take a look at its shape and color. Premature seeds will be small and light in color, taking on a beige hue. Fully mature cannabis seeds are more full in shape and size and have a much darker brown hue, sometimes accented by black tiger stripes.
Deseeding cannabis can be done by hand or machine. This process typically takes place after the plant has been dried for one to two weeks after harvest. This way, seeds will have reached their maximum maturity and plant material will be brittle enough to break apart with minimal effort.
When collecting seed by hand, use a fine screen to help catch trichomes that will break off during the process. This material is valuable and it would be a shame to waste.
To release the seeds, simply break up the dried buds over a screen and they will fall out. You can release the seeds en masse by rubbing the flower between your fingers and lightly breaking it apart.
Separate or sift seeds over the screen to remove any unwanted plant matter from the seeds themselves. Brush off the seeds—they should be completely free of any remaining plant material such as leaves, stem, or trichomes, as these elements put seeds at a higher risk for contamination and spoilage during long-term storage.
Male cannabis plants will produce pollen several weeks into their flowering cycle. Once their pollen sacs have opened up and released, the plant will begin to senesce and eventually die. It is important to collect pollen right as the sacs are beginning to open up, as this is the time pollen is most viable.
The best way to harvest pollen for storage is to remove an entire male flower cluster and place it in a sealed storage container for several days. After the cluster has dried, place it over a micron screen with parchment or wax paper underneath, and give it a light shake. This will allow the pollen to separate from any remaining plant matter and fall through the screen and onto the wax paper.
Moisture is a death sentence for pollen viability. Because of this, many breeders opt to mix flour into their pollen at a ratio of 4:1 (flour to pollen) when storing it long-term. This additional step will help keep pollen dry for a longer period of time.
Seed and Pollen Storage
Long-term storage requirements for seeds and pollen are similar. Both require cool, dark, dry, and oxygen-deprived environments for optimal preservation.
When storing seeds, place them in an air-sealed container that doesn’t have any light leaks. Film canisters, medicine bottles (non-translucent), and any sealable storage jar will work fine. The idea is to reduce the amount of oxygen present in the storage space as much as possible. You can also add uncooked rice to the storage container, which acts as an absorbent, to reduce moisture content.
For a cool environment, store seeds in either the refrigerator or freezer. Seeds need a consistent temperature without fluctuation to remain dormant long-term.
As mentioned above, the best way to reduce moisture in pollen is to mix it with flour. For long-term storage, it can be kept in a sealed vial or freezer bag. You can keep it in the refrigerator or freezer, though for optimal long-term storage, the colder the better.
The Shelf Life of Seeds and Pollen
You can expect cannabis seeds that have been sealed and properly stored to last for several years, and in many cases, longer. Seeds may be dormant, but they are still alive. Over enough time, they will lose their viability.
It’s important to continually practice germination testing to be sure your stored seeds haven’t lost all viability. To test this, periodically plant a seed and document its ability to germinate.
Fresh seeds should have a germination rate close to a 100%, whereas older seeds will see a significant drop off over time in their ability to germinate.
Out in the open, pollen may be viable for one or two weeks under normal conditions. However, when frozen and sealed, it can last up to a year and even longer. Pollen is more unstable than seed and even under the most optimal conditions, it isn’t expected to have as long of a shelf life.
For both seeds and pollen that have been frozen long-term, it’s important to avoid defrosting until they are ready to be used. Fluctuations in temperature and moisture content will quickly destroy their viability, so maintain a steady temperature for as long as possible. Warming and freezing multiple times isn’t good.
When it comes time to use frozen seeds, remove them from their container and let them sit out on a dry surface for several hours. Letting the seeds reach room temperature will help ensure a successful germination.
Pollen should also be placed at room temperature before using. Since pollen can be much messier to handle, it’s best to carefully transfer a sample from its long-term storage container to a fresh container before using it to pollinate a plant. This way, you don’t have to use all of the pollen and saved pollen can go back in the freezer with minimal exposure to warm air.
How to Properly Store and Preserve Cannabis Seeds [Explained]
If you don’t begin with great seeds, you can forget about producing a harvest of high-quality marijuana. A lot of growers seem to forget one simple fact: Your seeds are alive! Although cannabis seeds are fairly durable, improper storage can ruin them. If you’re paying $10-$20 a seed, losing a full batch is an expensive mistake.
Before your marijuana seeds germinate, they are in a similar state to animals when they hibernate. Like all living organisms, your seeds can die if you don’t take care of them correctly. The good news is that cannabis seeds can last for five years after harvest with proper storage.
In this guide, we outline how to store and preserve your cannabis seeds. We focus on the following:
- Insects & Pests
- Germinating old seeds
Keeping Light Away from Your Marijuana Seeds
You must keep your seeds in a location that is cool, dark, and dry. It is best if you keep the seeds in their original packaging. When they are exposed to temperature changes or light, cannabis seeds begin using their store of nutrients. This is a disaster because they ultimately won’t have the nutrients to germinate.
When they are exposed to temperature changes or light, cannabis seeds begin using their store of nutrients.
Make sure your seeds remain away from light, as it can directly trigger germination.
What’s the Right Storage Temperature?
The best temperature to store your cannabis seeds at is between 43- and 47-degrees Fahrenheit. The lower the temperature, the less likely your seed is to germinate unexpectedly. Experienced growers tend to have special refrigerators to store their seeds. Ideally, your fridge is a no-frost model. If you can place the seeds in the fruit and vegetable section, that is even better.
Another option is to freeze the cannabis seeds. If you go down this route, please ensure that you vacuum pack them first. Then put them in a dark container. Also, it would help if you germinated these seeds immediately once they come out of the freezer. Don’t allow them to thaw first.
What About Humidity?
Here is a quick overview of what will likely happen to cannabis seeds at different humidity levels:
Your cannabis seeds need a certain level of moisture for germination. If the humidity level gets too high, your seeds will rot in storage. An extremely low level of humidity of around 8-10% is suitable only for long-term storage. If it drops below 8%, you offer any insects present in the seeds the chance to become active and start reproducing.
The Right Storage Options for Your Cannabis Seeds
You now understand that you must store the seeds away from direct light. We have also outlined the need for relatively low humidity and a refrigerator-level temperature. Different options are available depending on how long you intend to store the seeds.
If you only require short-term storage, a dark drawer or cupboard is sufficient. The most important thing, regardless of the duration of storage, is to avoid temperature and humidity fluctuations. Rapid variations in temperature, in particular, can destroy your seeds. If you live in a location with warm daytime temperatures and cold nights, avoid outside storage.
For short-term storage, place the seeds in a container with desiccant. Seal it, and place it in a cool, dark place.
Once you enter medium-term storage (a few months), it is time to use an airtight container. Examples include a mason jar or Ziploc bag. Place this sealed container in the fridge. Remember that opening your fridge can cause significant temperature fluctuations. As a result, it is ideal if you have a second fridge that is seldom used.
Also, you should note that modern fridges have low humidity levels. If the humidity is too low, your seeds will begin using up nutrients.
If you want to store your seeds for at least six months, use a vacuum-sealed container. You can achieve this effect by removing all the air from a Ziploc bag. There are also special vacuum-sealed containers available online. Put the sealed bag in a dark container and put it in the fridge.
You also have the option of placing the seeds in the freezer. Remember, though; you need to germinate them immediately upon removal.
A Note on Insects & Pests
Imagine paying $100+ for seeds, going to the trouble of storing them, only to find that insects ruin them. Unfortunately, all you need is one insect in a container to destroy all of your seeds. The first consideration is to avoid exposure to ultra-low humidity. However, for long-term storage, this is precisely what you are supposed to do!
One option is to spread diatomaceous earth (D.E) where you store them. This is a type of sand that has a fossilized algae base. Crucially, for our purposes, it serves as an excellent natural insecticide. Unfortunately, you shouldn’t use D.E if you plan to store your seeds in a fridge with other food.
Imagine paying $100+ for seeds, going to the trouble of storing them, only to find that insects ruin them.
It would help if you also stored your seeds as high above the ground as possible. This reduces the possibility of a pest like a rodent coming in and feasting on the seeds.
Insects and pests also thrive in dirty storage areas. As a result, you must ensure the storage area remains clean. Otherwise, you won’t just attract pests to your seeds; microbes will form and damage the seeds. Do you want to consume marijuana from contaminated seeds?
You can ‘test’ your seeds once you have removed them from storage. Place them in water. If they sink, they should be fine. However, if they float, it is more likely that they are bad seeds. You can still try to germinate, but there is a greater risk of producing poor-quality cannabis, or else the seeds fail to sprout. You can keep floaters in water for approximately 72 hours to see if they sprout a tail.
If you have old seeds not stored in ideal conditions, there are still a few ways to germinate them.
- Remove the hard ridge with a sharp knife.
- Soak the seeds in carbonated water with germination booster, fulvic acid, or hydrogen peroxide. Use room temperature water, and perform this pre-soak for at least 12 hours in a dark area.
- Scratch the tough outer shell with sandpaper. Believe it or not, this process could help warmth and moisture get inside. This process is called ‘scarring’ and should happen before you soak the seeds.
- Make a small cut into the shell as a last-ditch attempt to get it to sprout.
Final Thoughts on Storing and Preserving Cannabis Seeds
If you purchase marijuana seeds and intend to use them almost immediately, you should have no issues. Even so, it is probably best to keep them away from direct light. In the short-term, a dark cupboard is sufficient as long as the temperature and humidity are reasonable.
Once the goal is to store cannabis seeds for months rather than days or weeks, everything changes. You need an airtight container, which you should store in a fridge. Include a vacuum-sealed container if you plan to store the seeds for several months or longer.
When storing cannabis seeds, you must ensure they are not exposed to germination conditions. This means keeping them away from direct light. Also, store in 20-30% humidity (8-10% for long-term storage) and a cool temperature. Keep the environment clean to avoid pests, and consider the tips above for germinating old seeds.