cannabis seeds viability storage how long last methods containers temperature humidity expiry preservation If you are a regular weed user and live in a US state where it is legal, chances are you have already tried your hand at growing your weed. If you haven’t tried it yet, well, there is a lot to learn. Growing cannabis is tricky even for experienced growers. It all starts with the cannabis seed. If the seed you plant is If you have some extra cannabis seeds lying around, you're probably wondering how long you can expect them to last.
How Long Do Cannabis Seeds Last?
Knowing how to properly store your cannabis seeds isn’t rocket science, but to a beginner grower especially, there’s a lot to be aware of. The key factors in maintaining seeds are storage methods, light, temperature, and humidity. If this looks like a minefield, don’t panic!
In this article, we’ll walk you through the main dos and don’ts of storage – not just the hows, but also the whys – and those precious seeds will be good to grow when you’re ready.
Understanding the Key Elements of Seeds Storage
To store marijuana seeds, it’s essential to starve them of the conditions they need to develop. Failure to do this can lead to a drop in germination rate, and you could easily find yourself opening a container of useless seeds which are no longer viable.
Consider all the variables involved in plant growth, and if needs be, carry out further research to better understand how these can impact seed storage. Since most plants see winter as the time of dormancy and spring as the time of new growth, the way you store your seeds should try to emulate the critical conditions of winter, which should keep the seeds from germinating.
Table of contents
Understanding Cannabis Seeds
Cannabis seeds are similar to any other type of seed used to produce plants. They’re hardy-looking things, but they have a shelf life. They’re also susceptible to environmental changes – too much fluctuation in any direction can cause them to spoil. An undesirable extreme change in temperature or humidity at the wrong time (during storage) will put paid to your seeds. Light is the other main naturally-occurring variable you should protect your marijuana seeds from.
It’s important to remember that your seeds are dormant before germination but very much alive. For this reason, it’s best to treat your cannabis seeds with a degree of care and common sense. Unless you’re about to germinate, make sure your seeds ‘sleep’ in ideal conditions.
How the Main Variables Affect your Cannabis Seeds
It’s one of the classic storage instructions on packages for all manner of products – store in a cool, dry, dark place. As mentioned above, high temperatures and moisture levels tend to cause things to spoil, especially if they contain natural ingredients.
Light, heat and moisture all signal to your seeds that it’s time to sprout, and each of these variables affects your seeds differently. Exposure to any of these elements will cause your seeds to expire unless they’re well protected.
When you store cannabis seeds, it’s essential to keep them away from light. For example, don’t be tempted to throw a handful in a baggie and keep them in your grow room. Keep your seeds in their original packaging, or transfer them to an opaque, airtight container. Something such as an envelope or a blacked-out mason jar is perfect for room-temperature storage. Keeping seeds well-shielded will prevent them from absorbing any light before your planned germination time.
The shells – those hard, waxy coatings on seeds – offer a degree of protection against light. But while cannabis plants love light, cannabis seeds do not. In nature, cannabis seeds fall from the plant towards the end of the year when daylight levels are reduced. They then sit beneath a light covering of soil until the following spring when they could naturally germinate and bloom. It helps to think about the natural cycle when storing cannabis seeds. Keep them dormant until you decide you want them to germinate.
If you want to store your cannabis seeds long-term and retain their viability, it’s imperative to keep humidity levels under control. Moist, humid conditions are key ingredients in the seed germination process. If you expose the seeds to high humidity levels too soon, they may begin to germinate on their own. You don’t want to store your seeds at too low a humidity either – that can bring a different set of problems entirely. Here’s how humidity levels can affect seed viability:
These figures are a rough guideline, as risks vary slightly depending on storage method and container type. Still, they serve as an excellent approximate rule of thumb for humidity levels. Excess moisture will soften the seed’s outer shell and cause the taproot to emerge. If you’re not actively germinating that seed, it’s spoiled.
Monitoring Humidity Levels for Cannabis Seeds
Keeping tabs on relative humidity levels is reasonably straightforward. You can pick up a humidity meter on Amazon.com, and while they can vary in terms of features and cost, there are budget humidity meters which are inexpensive and still do the job.
How to Control Humidity Levels for Cannabis Seeds
Start by choosing the storage container wisely and then the environment. Use an opaque tin, plastic container or the original packaging, so long as it’s a container that seals tightly. After that, it’s a question of choosing the right environment to ensure humidity is right for safe storage. Toss in a desiccant like a silica gel pack for extra help.
Storing Seeds Shorter-Term in a Room
If your planned storage spot is in a room that’s prone to condensation on the windows, pick another location. Condensation is a good indicator that room humidity is too high, and this will harm your seeds quickly. Choose wisely – laundry rooms or bathrooms naturally make bad spots to stash seeds due to high heat and humidity levels. A living room drawer or a dark cupboard in an area that doesn’t see too many extreme temperature fluctuations is ideal.
Opening windows and vents will help keep humidity levels nearer the sweet spot. If your storage space is prone to humidity, it may be worth investing in a dehumidifier. It’s impressive how much moisture these can pull out of the air after a few hours, so it’s good to know that some devices can decrease room humidity fast.
Storing Cannabis Seeds in the Refrigerator
This is a fairly common strategy for storing cannabis seeds. Seeds are placed in a suitable container and kept safely in the refrigerator for years, retaining great viability rates. The lower temperature of the fridge makes an ideal environment for preserving seeds, working in a similar way to storing food in your refrigerator. At low temperatures, the cellular biochemistry of the seed slows down, and the seed remains viable for years. This is why a cool place is always best for storing seeds.
Storing Cannabis Seeds in the Freezer
It’s certainly doable, but it’s arguably not necessary. Storing your cannabis seeds in the correct container in a freezer will undoubtedly extend the viability of those seeds. But is it a gamble worth taking? Sure, if you have many big projects planned and many seeds to store. In most cases, though, storing your seeds in a refrigerator is just as helpful and probably less risky. Some collectors store vintage seeds in a freezer for long-term safety, but this isn’t a necessity for most of us.
The Ideal Temperature Range for Safe Seed Storage
If storing your seeds in a cool, dry place, pop them in a drawer well away from heat sources. This quick and easy way to keep seeds stashed will ensure a good degree of viability in most cultivars. The main thing is to keep the temperature low and away from the risk of temperature changes. The lower the temperature, the longer you should effectively be able to store your seeds safely.
If storing cannabis seeds in the fridge, make sure your fridge can maintain a steady temperature of between 4°C and 6°C. This will ensure safe long-term storage. In both cases, it’s best to store seeds in a suitable container, especially if you’re storing them in a fridge. The lower temperature of the fridge demands a little more protection for your seeds. An opaque tin or container with a seal that is air and watertight is your best friend in this instance.
Not all seeds are created equal. If you’ve grown different cannabis strains from seed, you’ve probably noticed that some seeds are larger or more resilient than others. Some batches will occasionally contain failures, but most seeds should store long term without any hassle. Not every seed in a batch will necessarily respond the same way, though. In a bag of ten seeds, you might find a couple don’t germinate, and while this is annoying and unfortunate, it’s sometimes just the nature of the genetics.
Hypothetical Case Studies
Customer 1 is a hobbyist cannabis grower. He buys a couple of bags of seeds from Seedsman during a promotion, intending to plant some now and store others for later. Customer 1 can safely store his surplus seeds in the original package or transfer them to a suitable container. He can seal it and place it in a dark, dry cupboard or drawer, away from any heat source. Using this method for short-term storage, Customer 1’s cannabis seeds should easily remain viable for between three and five years.
Customer 2 is a commercial cannabis grower. She buys her cannabis seeds in bulk, but only ever has a dozen plants growing at any given time. In this situation, she can safely store her surplus seeds in an appropriate container inside a refrigerator. She sets her refrigerator to maintain a steady temperature between 4°C and 6°C. Using this storage method, Customer 2’s cannabis seeds should easily remain viable for five years or more.
Customer 3 is a well-known seed bank. They are looking to preserve certain genetics long into the future, and store those particular older seeds in a freezer. They ensure to keep seeds in the correct containers and handle them with care at every stage. Aware that the frozen tissue inside the seeds becomes delicate and at risk of shattering, they treat seeds with the utmost caution. These steps should see their seeds retain a high rate of viability for decades.
Having Quality Genetics Helps
The answer to the question, then, is seed viability is largely dependent on how you store your seeds. By knowing how long you want to keep your seeds, and storing them accordingly, you can take the proper steps to ensure they will remain viable for as long as you need them to. Remember that seeds contain living matter, and there’s always a percentage risk of failure. This is true regardless of how well you handle and store them. By buying cannabis seeds from a top-quality seed bank like Seedsman, you ensure greater quality of genetics and stack the odds of a high germination rate in your favour.
Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.
How Long Do Cannabis Seeds Last In Storage?
If you are a regular weed user and live in a US state where it is legal, chances are you have already tried your hand at growing your weed. If you haven’t tried it yet, well, there is a lot to learn.
Growing cannabis is tricky even for experienced growers. It all starts with the cannabis seed. If the seed you plant is no good, then you won’t get a plant at all. If you plant a seed of poor quality, then your plant will likely be of poor quality too.
If you want your cannabis plants to be healthy and potent, then the seeds your start with need to be healthy and from a good strain of cannabis.
Some people that grow their cannabis prefer to purchase their seed online, while other growers prefer to save and store seeds from their plants. How cannabis seeds are stored for later use is of the utmost importance.
How Can I Tell If Cannabis Seeds Are Good?
If you are going to go to the trouble of storing cannabis seed long-term, then you want to make sure you are storing only good seeds. After all, what would be the point in storing bad seeds? Most of the time you can tell a good quality of a cannabis seed by the way it looks.
Healthy cannabis seeds will have darker shades of gray and black on the outer shell. These darker colors can also signify genetically superior seeds.
Healthy seeds should also be firm to the touch and have a glossy and wax-like look to the shell. If you roll the seed between your thumb and index finger and it feels firm, then it should be a good seed to plant and should store well in the right conditions.
Effects Of Humidity On Cannabis Seeds
How you store your cannabis seeds works in much the same way as when you store your cannabis. Humidity can play a huge factor in how well your seeds stay preserved and for how long. In fact, humidity plays a major role in the entire lifecycle of the cannabis plant, from seed to storage of the finished flower, and ending in consumption. We even have a guide to rehydrate your cannabis if you fail to keep it moist enough and even have information on freezing your cannabis, which can cause mold issues quickly. But I digress.
Too much humidity can cause seeds to become soft and mushy or germinate. If there is no humidity at all, they can become dry and brittle and crack open.
Cannabis seeds store ideally at 20% to 30% humidity. If the humidity level is higher at 40% to 60% humidity, they will likely germinate. At 80% to 100% humidity, they will drown and wilt in as little as 12 hours.
If the humidity level falls below 20%, the seed may heat up and sweat, develop fungi on the outside as well as the inside. At the lowest humidity level of 10% or less, the seeds can attract insects or pests.
Best Storage Methods For Cannabis Seeds
Keeping your cannabis seeds cool and dry at a consistent temperature and humidity level is essential. First, you need to pick your storage container. It should be air-tight and keep out UV light if possible.
It can be a glass container with a sealing lid. Ziplock baggies are alright to store seeds in if you do your best to remove as much air as possible.
Storing your seeds in a cupboard or closet shelf is fine for short-term storage. Never store your seeds outside in a garage or shed because the constant temperature changes of day temps and cooler night temps will not be good for them.
For more long-term storage, you can always refrigerate your seeds. The refrigerator will keep the seeds at a cool, constant temperature.
Refrigeration can preserve your seeds for several years or more, but it is probably best to use them before this amount of time goes by. Freezing your seeds is possible, but necessary.
How Long Do Marijuana Seeds Last? (Explained)
If you have some extra cannabis seeds lying around, you’re probably wondering how long you can expect them to last.
The germination rate of Marijuana seeds naturally declines over time. However, if stored correctly, your seeds can last for up to 5 years. However, to last that long, they need to be good quality and be stored in a cool, dry, and dark place.
Read on to find out how to store your seeds correctly to make them last longer.
Free Cannabis Seeds? Check out my list of the best seed bank promotions – Including FREE Seeds, discount codes, and giveaways!
How Long Do Marijuana Seeds Last?
Cannabis seeds can last for a very long time if they are stored in the correct conditions. The ideal storage temperature for cannabis seeds is between 7-10°C (45-50°F), with a humidity level of around 55%. Under these conditions, your cannabis seeds should last for many years.
However, it is worth noting that the shelf life of cannabis seeds will decrease if they are exposed to light, heat, or excessive moisture. Therefore, it is important to store your seeds in an airtight container in a cool, dark place.
If you are planning on germinating your seeds at some point in the future, it is worth testing a few to check their viability first. The best way to do this is to place the seeds in a cup of water overnight. After 24 hours, check to see if any of the seeds have sunk to the bottom of the cup. If they have, this indicates that they are still viable and should germinate successfully.
How To Tell If Your Cannabis Seeds Are Still Good
Many growers have experienced the frustration of planting cannabis seeds, only to have them fail to germinate. If you’re wondering whether your stored cannabis Seeds are still good, there are a few things you can do to test them. One simple way is to do the float test: Take a glass of distilled water and drop it in your seed. If it sinks, it’s probably still good. If it floats, it’s not going to live.
Also, give the seed a light squeeze between your fingers. Healthy cannabis seeds should be firm, with a dark brown or black coloration. If they’re pale or green, they’re not going to sprout. If they’re hard and brittle, they might be too old.
The best way to tell if your seeds are still good is to try germinating them. Plant two or three seeds in moistened soil, and wait a week or two to see if anything happens. This method isn’t foolproof (sometimes seeds just don’t want to germinate), but it’s the most reliable way to tell if your precious cannabis seeds are still alive and viable.
Will Cracked Marijuana Seeds Still Germinate?
The simple answer is yes. However, it is worth noting that the germination rate for cracked seeds is often lower than for intact seeds. In addition, the process of germinating a cracked seed can be more difficult and time-consuming. When a seed is cracked, the protective outer coat is damaged, exposing the delicate inner tissue to the elements. This makes it more susceptible to infection and less able to absorb moisture. As a result, it can take longer for a cracked seed to germinate, and the plant that emerges may be weaker than one grown from a healthy seed. Despite these challenges, it is still possible to successfully grow a plant from a cracked marijuana seed. With patience and care, you can end up with a bountiful harvest of high-quality buds.
How To Make Your Marijuana Seeds Last Longer?
Let’s take a look at some of the main ways you can make your marijuana seeds last longer.
1. Store Them Properly
You can prolong the shelf life of your marijuana seeds by storing them properly. Keep them in a cool, dark place, like a pantry or cupboard. You can also store them in the fridge, but make sure they’re in an airtight container so they don’t dry out.
If you live in a humid climate, it’s a good idea to store your seeds in the fridge or freezer to prevent them from going bad.
If you have a lot of seeds, you can also store them in a Mason jar or vacuum-sealed bag. Just make sure to label the container with the date so you know when they were stored.
A Ziplock bag works well when you want to store seeds for a short duration of around 5-6 months. Any longer than that and your seeds may start to go bad.
Put your seeds into your bag, try to remove as much air as possible and then seal it tightly. Then keep your bag in a cool and dark place.
A step further than a regular Ziplock bag, a vacuum-sealed bag will ensure that there is no air left inside your bag.
This will allow you to store your seeds for a longer period.
You will still need to ensure to keep it in a cool, dark environment.
Some seed banks deliver seeds in a vacuum-sealed package that can store them until they’re ready for planting.
Another great method for long term storage is keeping your seeds in an airtight container.
Glass containers are preferable as they are more resistant to heat and UV ray damage.
Just make sure to keep them away from light.
If you are looking to store your seeds for over a year, you can refrigerate them.
Refrigerators offer constant low temperatures and dark and moisture-free environment.
Keep your seeds at the back of your fridge so that they are away from any potential moisture or temperature changes from opening it often.
Make sure the container or bag your seeds are in is airtight and heatproof.
You will also want to make sure that your fridge is “no-frost” or has a no-frost area to shield seeds from frost damage.
Freezing marijuana seeds is a debated method.
Freezing is used by some to store their seeds for years on end.
Others say that it ends up killing seeds instead of protecting them.
Some growers even believe that freezing seeds can damage their internal cells.
Using special laboratories and equipment can allow for the careful freezing of seeds, but this is not a very cheap or accessible option for many.
Now that we have covered everything there is to know about how long marijuana seeds last and how to store them, you are all ready to begin your growing adventure. We’ve made sure to cover all our bases- from basic seed facts to how to choose the best seed bank.
You Might Also Enjoy.
Hey, I’m James! The founder and head writer here at GreenBudGuru.com. I started this site to share my passion and knowledge of all things cannabis. I used to work as a budtender in central Amsterdam, and have over 7 years of growing experience.
Find me online:
Leave a Comment Cancel reply
Hi, I’m James, the founder of GreenBudGuru. I started this site in 2018 to help new cannabis growers avoid the common mistakes that I made as a beginner with easy-to-follow guides. GBG is now read and trusted by over 100,000 people each month.