Long-Term Cannabis Flower Storage Tips For Harvest Season

Whether you grow and harvest cannabis crops in large quantities or like to buy flower in bulk during a sale, there are times when you will need to store your cannabis long-term.

It’s always important to properly store cannabis even in the short-term, such as by putting it in a Mason jar versus keeping it in a plastic bag, storing cannabis for long periods of time requires a bit more precaution. This is because storing cannabis long-term means it’s more likely to have a decrease in potency, taste, and quality due to exposure to light, air, or humidity.

Overly dry weed means it will lack flavor and have a dissipation of cannabinoids and terpenes over time. Weed that has been exposed to excess moisture can lead to mildew growth, which is not only unhealthy to smoke but can have side effects like excessive coughing and nausea.

Fortunately, when quality cannabis is stored properly, it can last for a year or more while keeping most of its original qualities.

Best Practices for Long-Term Cannabis Storage

The container your cannabis is stored in is arguably one of the most important parts of your long-term storage planning.

Sealed mason jars, or generic glass jars with lids that seal well, are still a great option for long-term storage, especially if you’re storing weed for up to a year.

Glass storage is ideal, compared to plastic or other materials when storing, since glass won’t have any kind of damaging chemicals and protects the weed from air exposure very well if it has a good seal. Plastic jars and other plastic containers can hold static electricity and contain chemicals that may harm cannabis terpenes and trichomes.

Seals built into the lid of the jar made from rubber, silicone, or plastisol are the most ideal. There are also jars sold that are specific to keeping cannabis plants fresh. They are an option worth looking into since they often come in sizes similar to the quantities in which cannabis is sold. Many come tinted to help with light control.  

Choose a jar size that won’t have the buds squished together too tightly, which limits good airflow, but is not so oversized that there is too much empty airspace. If you harvest a large crop, keep this in mind when preparing and distributing cannabis into your jars. Make sure you keep your strains in separate jars and label them well for when you pull them out of storage later.

If you know your stash is going to be stored for upwards of a year or more, it might be worth looking into a vacuum-sealed storage jar since this will truly ensure it’s air-tight. Nitrogen sealing to remove the oxygen will also keep your cannabis ultra-fresh since oxygen is a degrading element for marijuana.

However, vacuum-sealed bags are not as ideal, since outside air can still leak into this type of container and many are plastic, which as mentioned, is not an ideal form of storage for cannabis.

If you want to get fancy and don’t mind the price tag, there are also high-tech stash boxes and containers that help control elements like airflow and humidity.

Other Ways to Protect Cannabis During Long-Term Storage

Light, air, and humidity are the three most important things to consider when storing your weed long-term.

The jars your cannabis is stored in should be kept in an area that has no direct sunlight, and ideally, is almost always dark. UV rays will break down cannabinoids, meaning you lose freshness. You can also use a UV light-blocking sealed jar, but storing it in a dark area regardless is still preferred.

Humidity levels, as mentioned, can cause issues like mold, mildew, or over-drying along with other damaging side effects. The ideal relative humidity (RH) range when storing weed long-term is 55%-65%. When stored in a proper container, this will significantly help with any humidity-related issues. 

For those harvesting their own cannabis, ensure your crop is properly dried before storing long-term to avoid excessive humidity issues. When jarring cannabis for the first time after it’s been properly hang-dried, use a humidity meter and maintain a humidity level of about 60%. If the humidity in the jar is above 65%, the flower is too wet, and you will need to leave the lid off for a while to allow it to dry a bit more.

During this first-jarring process, open the jars every 3 to 5 days and leave the lid off for about 30 minutes before putting the lid back on. When the humidity in the jars maintains a level of about 55% or lower for almost a week, you’ve reached your cure state and can then store the jars long-term without worry. This first-jarring and curing process normally takes about 30 days for a properly harvested cannabis plant.

Fortunately, there are also weed-specific packets that go in your jar and can help control the humidity levels. Some even have added terpene protection.

Small temperature and humidity sensors, called hygrometers, fit perfectly in a glass mason jar and are also beneficial. This way, you can check in on the temperature and humidity without ever breaking the seal or vacuum seal if using a clear glass jar.

The temperature of the area your cannabis is stored in long-term should be considered as well. Ideally, the temperature the cannabis is stored in long-term should stay below 70° F and be as consistent as possible.

Exposure to high heat is not good for cannabis storage, so store them away from electronics or appliances that give off heat. Attics, while dark, are also not a great place to store cannabis long-term due to how hot they can become, especially in the summer months.

While it might seem like a good idea to put marijuana in the fridge to keep it fresh, this will actually increase the odds of mildew or mold in your cannabis due to fluctuations in temperature and humidity. The cold air will also do more harm than good, as the buds will pull water from the air, causing additional mildew-related issues and a poor taste when you do finally take them from storage.

Similarly, freezing your bud is not a good long-term storage method. The freezing temperatures can cause icicles to form on the trichomes, making them brittle and easily broken. The moisture in the freezer is also not good for the same reasons as long-term storage in the fridge.

Some of the best places you could store your sealed cannabis containers are in a closet, a drawer in a bedroom, a low-level cabinet in your kitchen that is far from kitchen appliances, or a dry area in your basement away from things like water tanks or clothes washer and dryer that could cause moisture-related issues.  

Final Thoughts

Cannabis will always change in some ways over time when stored long-term, but if it is kept air-tight, cool, and dry, it won’t go bad—it will just be different when you finally pull it from storage.

Ideally, you should store cannabis for up to a year or two maximum, if at all possible, using the storage tips mentioned in this article for the best results.

Think of it like pulling an old bottle of wine from the cellar. The taste and effect will be different, but if stored right, it will give you a unique taste and high that might even be better than when it was fresh!