How to make feminised cannabis seeds
Until the 1990s, any cannabis cultivator was aware that, at some point, they had to separate the male and female plants if they didn’t want the first ones to pollinate the latter, which results in plants completely full of seeds. However, those were the days when pioneering seed banks like Dutch Passion were revolutionizing the cannabis scene with the birth of the first feminized cannabis strains, or in other words, seeds that only develop into female plants. At the beginning of the 20th century, many seeds banks were offering this type of seeds, feminized versions of classics strains that had been cultivated during many years as regular plants.
We are sure that by now you’d probably have grown some feminized seeds, maybe even though you are a purist and the fiercest defender of regular seeds. But. do you know where feminized seeds come from? Are you familiar with the processes used by both breeders and growers to obtain them? In this article we explain everything!
Feminized cannabis seeds quality control
Advantages of growing feminised seeds
Indeed, the advent of feminized seeds brought about a genuine revolution within the cannabis sector. Growers were now sure that all their plants would be females, without the need to differentiate between male and female plants or having to remove the males before they could ruin the crops, which offers a number of benefits of significant importance:
- Space and resources saving: no more growing plants which eventually will be removed for being males.
- Reliability: it’s not that most plants are female, or that they are genetically more likely to produce female plants. The plants grown from feminized seeds have only female chromosomes (XX), therefore this method is 99% reliable.
- Sinsemilla plants: by not having males in the grow room, your female plants won’t be pollinated, so they won’t produce any seeds during the flowering period (something that every cultivator wants, unless they want to obtain seeds)
These advantages were of great interest for the growers, and soon feminised seeds accounted for a large portion of the seeds available in the market. In addition, being able to use only female plants (generally known and selected clones) to produce seeds had another great advantage for seed producers and breeders of new varieties: they no longer need to keep males in their gene pools! And not only that. from that moment on, any female plant they could get their hands on could be used as a male to pollinate other plants, thus exponentially increasing the possibilities of creating new crosses.
Outstanding Orange Candy feminised from Philosopher Seeds
It is not surprising, therefore, that at present, feminized seeds represent virtually all the seeds in the market, since they offer a number of significant advantages for both professional and home growers and breeders, for photoperiod and autoflowering plants. The main disadvantage of this method is a well known and hotly debated issue: the growers who buy this type of seeds cannot produce their own seeds in the absence of male plants, so the only way they can manage it it’s using the same process to obtain this type of seeds. But. what are these processes and what are they based on?
Female crosses: feminised cannabis seeds are born
As we’ve already mentioned, feminized seeds are the result of a process that reverses the sex of a female plant, that is, she is forced to produce male flowers. This way, and once into flowering, the female chosen will start to develop what we know as male flowers (stamens and anthers), which, just like male plants, will release the pollen that will pollinate the female plants. What is then the difference between a male plant and a reverted female plant?
The sex of cannabis plants is determined in the same way as ours, through the so-called sex chromosomes or genosomes. Male plants have a couple of different sex chromosomes called “XY” or heterogametic, while female plants have two chromosomes called “XX” or homogametic. When crossing a male (XY) with a female (XX), we will obtain around half of the plants of each type in their offspring. In other words, when a breeder uses a male and a female plant, the seeds produced by them will be approximately 50% males and 50% females.
After this explanation, many of you will have already figured out that if we cross two female plants (reversing the sex of one of them to force it to produce pollen), the result will be seeds that will produce female plants, as there are only female sex chromosomes in the equation. If crossing XY with XX produced 50% of each class (male and female), crossing XX with XX will produce plants that only exhibit chromosomes XX, that is to say, female plants. No matter how many times we “transform” a female plant into a male plant, we won´t be changing their genetic composition, which will still be female or XX. This way, the pollen produced by this plant will pass down female sex chromosomes exclusively.
Feminised seeds grown indoors, 100% female plants
As you can see, and although we normally use the expression “reversing the plant sex“, that is not exactly what is done, because the sex chromosomes of the female plant (XX) have not changed, even if we managed to produce male flowers. This “sex change” of female plants can be achieved in a number of ways, but usually with the same goal: to reduce the level of ethylene in plant tissues and/or inhibit the ethylene action, which makes the plant develop male flowers on entering the flowering period, as if it were a male from regular seeds. This is because ethylene is a natural regulator of the sex expression in plants!
Let’s see now the most popular ways to reverse the sex of a female plant in order to produce feminized seeds.
Methods used to produce feminized cannabis seeds
There are several ways to secure that a female plant produces pollen, and almost all of them require some type of chemical that is often sprayed on the plant. Once sprinkled with the chosen product and under a flowering photoperiod, the plant will flower normally, but as a male instead of female, producing ‘feminized’ pollen (which only contains chromosomes XX) that can be used to pollinate other females in order to produce seeds. These are some of the most commonly used techniques:
Stress or rodelization
One of the first methods used to obtain seeds that produce female plants was stress or rodelization. There are several ways to stress the cannabis plants to make sure they develop male flowers, such as through temperature, nutrition, photoperiod, and pH. However, supporters of this technique often prefer something as simple as delaying the harvest 2-3 weeks in order to force the plants to develop a few male flowers without stressing them as much as with any of the other methods we have mentioned.
Although this action will produce far less pollen than other techniques like STS, it will be enough to obtain a handful of seeds for the domestic growers to try to create their own feminized crosses. Also, the great advantage of this technique is that is 100% natural, and it doesn´t use any chemicals. It is an excellent alternative for anyone who just wants a few seeds and wishes to keep it simple without any formulas or laboratory products. However, bear in mind that this is the only method listed in this post that may produce some plants with hermaphroditic traits.
Male flower produced by rodelization
STS or silver thiosulfate solution
Without any doubt, one of the most commonly used methods for both producers and seed banks. This is a solution made of distilled water, silver nitrate and sodium thiosulphate (sometimes called sodium hyposulphite) that, after being sprayed on the female plants, inhibits their ethylene action resulting in the formation of male flowers once flowering has been induced. STS is relatively easy to prepare, although its lifespan after combining the two components is quite limited, barely a few days as long as it´s well preserved (in a dark and cool place).
It is important to mention that you must not consume any part of the plants sprayed with this type of product, although that would be weird, as the plants have “become” males and won´t produce any buds. Nevertheless, you shouldn’t use the reverted plants to make resin extracts; the best thing is to discard them after harvesting the pollen. Both components, sodium thiosulphate and silver nitrate, are also used for photo-development.
This is another way to revert the sex of the plants, but this time using a solution made of 30ppm colloidal silver (that you can easily find in many pharmacies and also online) and distilled water. The solution must be applied for a few days until the plant starts producing male flowers, something that it´s not necessary with STS, where in most cases one single application is enough.
Colloidal silver is formed by electrically charged silver nanoparticles and has antibacterial and antifungal properties. This product was introduced in the market in 1980 for therapeutic use. However, as with STS, you should get rid of the sprayed plants once their pollen is harvested, as colloidal silver is absorbed systemically by the plant and remains in its tissues.
This sativa plant treated with STS started flowering as a female but soon developed male flowers
This is a method researched by Mohan Ram, who also conducted extensive investigations on plant sex reversal with STS. According to his findings, sodium thiosulphate (STS) is more effective in producing male flowers and viable pollen in female plants. Probably because of this, silver nitrate is mixed with sodium thiosulphate, instead of using it in isolation.
Gibberellins are plant hormones that help regulate various processes related to the development of the plants. There are several types of gibberellins available in the market, although the most common and effective is gibberellic acid or GA3 (Gibberellin GA3). This product is used in a very similar way to colloidal silver, sprayed on the plants during several days before switching the photoperiod over to flowering.
It is worth stating that one of the side effects of gibberellic acid is a significant stretching of the treated parts of the plant, so don’t be surprised if this happens to your plants! The recommended dose to achieve the best results is approximately 100ppm.
Urban legends and lies about feminized seeds
Despite the fact that, after two decades of cannabis cultivation, many of the false myths surrounding feminized seeds have been debunked, from time to time we still hear some arguments like the ones shown below. As is often the case, many of these stories are spread by people who have never grown this type of seeds or have none or very limited experience with them. Ignorance is always a bad thing, and that’s why we want to emphasize several points in relation to feminized seeds and the myths that often go with them; myths such as the following:
Feminized seeds produce hermaphrodite plants:
The problem with monoecious hermaphrodite plants has more to do with the parents used (and if they exhibit any hermaphrodite trait) rather than with the type of seeds produced. If to create a feminized seed you use a female plant with a tendency to produce male flowers, part of its offspring will likely inherit that characteristic, whether the said female plant is used as a pollen donor (after reversing its sex) or as a recipient of pollen (letting it flowering as usual). Yet the same thing happens when producing regular seeds: if the male or female parents are not stable in this respect, neither will be their offspring (or at least part of it).
Marijuana and hermaphroditism
Many growers have been surprised by the presence of hermaphrodite plants in their marijuana crops. In this post we will tell you how to detect them and how to proceed if you find a hermaphrodite cannabis plant in your growing space. We will also discuss the causes of this hermaphroditism.
Feminized seeds produce mutant plants:
Nothing could be further from the truth. It is true that sometimes some plants develop weird traits or mutations, although this also happens with regular seeds. Unfortunately, there seems to be not enough studies comparing the ratio of specimens with mutations of one or other type of seeds; however, given the millions of feminized seeds that have been germinated in the last 20 years, if mutations would pose a problem, the quantity of feminized seeds sold would certainly not be so high, and this would be a “public security” issue within the cannabis sector, both for the growers and the producers of the seeds.
Feminized seeds have chemicals:
This is another lie that some people believe. As it’s been mentioned before, a female plant is sprayed with some chemicals in order to inhibit its ethylene action. After a few weeks of this and once in the flowering period, the plant will produce male flowers and pollen, which will be harvested to pollinate the female plants designated to produce seeds. Once the seeds are formed, they are collected and packed immediately, so they don’t come into contact with any chemicals or the plants that produce seeds, nor, of course, with the seeds themselves. Also, to produce cannabis seeds, you normally need two separated indoor cultivation areas, one for the reverted plants (treated females) and the other for the females to be fertilized to produce the seeds, so the latter can’t get “contaminated” with any chemicals.
Feminized seeds are GMOs:
Once again, this is a false statement. We have already pointed out that by using these sex reversal techniques we inhibit the ethylene action in the female plant, and under no circumstances the seeds (or plants) are genetically modified. The sex chromosomes of the female plant converted into a male plant are still female (XX), nothing has changed at a genetic level.
We hope you found this article interesting; even today, many people are still unaware of the intriguing process behind this type of cannabis seeds. Do not hesitate to leave your comments; we will be delighted to answer them.
- Marijuana Botany, Robert C. Clarke
- The Cannabis breeder’s Bible, Greg Green
- The Cannabis grow Bible, Greg Green
- Breed your own vegetable varieties, Carol Deppe
- Induction of Fertile Male Flowers in Genetically Female Cannabis sativa Plants by Silver Nitrate and Silver Thiosulphate Anionic Complex, Mohan Ram, Sett R.
The articles published by Alchimiaweb, S.L. are reserved for adult clients only. We would like to remind our customers that cannabis seeds are not listed in the European Community catalogue. They are products intended for genetic conservation and collecting, in no case for cultivation. In some countries it is strictly forbidden to germinate cannabis seeds, other than those authorised by the European Union. We recommend our customers not to infringe the law in any way, we are not responsible for their use.
It’s never been easier to grow your own marijuana plant and all you need is a list of the best seed banks to get started.
You can buy weed seeds online and do so safely, easily, and for a bargain price. Half the battle though is compiling a list of the best-reviewed cannabis seed banks and then choosing which one seems right for your project.
In this discussion, we’re going to list 13 of the best seed bank options, along with the pros and cons of each company.
13 Best Seed Banks That Ship to the USA (and beyond)
1. I Love Growing Marijuana – Best Seed Bank Overall
- Location: California, USA
- Ships to: Only the USA (until further notice)
- Shipping time to the USA: 2 days shipping, 2-10 days arrival
- Free shipping to the US (regular seeds)
- Guaranteed delivery and germination
- Lots of free guides on growing
- Average price per seed a little steep
I Love Growing Marijuana immediately puts you at ease, offering a wealth of knowledge about growing cannabis for newcomers and veterans alike.
In addition to growing guides, forums, and journals, they have deals like Buy 10 Seeds, Get 10 Seeds Free, free shipping, guaranteed delivery, guaranteed germination, and multiple coupons.
Overall, ILGM offered the best deals and the best guiding hand to get started, and for first-timers (a large portion of those looking for cannabis strains by name) links to educational resources for the weed-growing are important.
2. Crop King Seeds – Best Marijuana Seeds Genetics
- Location: Vancouver, BC, Canada
- Ships to: Any country worldwide
- Shipping time to the USA: 2-7 business days anywhere in North America
- Toll-free telephone support, 24/7
- Established 2005
- Accepts Bitcoin and traditional payment methods
- Guaranteed delivery and germination
- Higher-than-average price
- Coupons could be better
Crop King Seeds is well connected, with over 100 retail partners and a wide range of seeds, with better quality genetics and breeding selection.
They are a trusted brand with 200 stores in Canada as well as an online store that ships worldwide. Their value packs, like Mix Pack Feminized and Autoflower Feminized are ideal for new growers.
The company has a reputation for selling the highest quality male and female seeds, and for making innovative discoveries in breeding seeds organically.
They also accept Bitcoin for stealthy payments.
3. Seedsman – Best Variety of Cannabis Seeds
- Location: Barcelona, Spain
- Ships to: U.S., Canada, U.K., Australia, Europe, New Zealand
- Shipping time to the USA: Within 3 days of receiving tracking number
- Established 2003
- 1500 types of seed strains
- Works with 63 different seed banks
- Many free seed promotions throughout the year
- Refund requires a somewhat complicated process
Seedsman offers plenty of discounts, averaging about 25 percent off of orders and approximately 40 promotions a year.
In addition to maintaining good word-of-mouth and social media reviews, the company also has a loyalty program for returning customers. Bitcoin buyers save money too, which is cool.
Still, with over 1,500 cannabis seed strains, variety is the company’s strong suit.
The company does hassle you for a refund, but it’s understandable that they have to protect against unscrupulous “samplers” with no intent to pay for quality marijuana seeds.
4. Herbie’s Seeds – Top Seed Bank That Ships To Any Country
- Location: San Vicente, Alicante, Spain
- Ships to: Any country worldwide
- Shipping time to the USA: 24 hours shipping, 3 weeks delivery
- Regular recommendations for new customers
- Deals as high as 35% off for selected strains
- Free seed with every order
- Online support team answers questions
- Very new company
- Free shipping deals don’t apply to U.S. buyers
Herbie’s Seeds offers good deals on selected strains, multiple forms of payment (including Bitcoin and wire transfer), and best of all, offers free Gorilla Glue Auto seeds with every purchase.
The shipping time to the US could definitely be better, but if you’re looking to support a new Spanish cannabis seed bank that’s making a name for itself in the scene, you should definitely give Herbie’s Seeds a try.
5. MJSeeds – Best Weed Seeds Stealth Shipping
Location: Vancouver, British Columbia, Canada
Ships to: Worldwide
Shipping time to the USA: Ships in 24 hours, 7-24 days for delivery
- Guaranteed germination rate (if you follow instructions)
- Customer telephone support
- Established 2009
- Accepts multiple payment options, even cash & money order
- Shipping is somewhat pricey
- Average discounts
MJ Seeds Canada is one of the most reliable companies and best stealth shipping options, because of discreet packaging and multiple payment options.
You could send Bitcoin, Paypal funds, or even a money order through the mail and get your seed within a couple of weeks. Shipping is same-day and faster-than-average, with a dedicated customer support line.
The company has a rotating stealth system, using different “disguises” for seeds, ensuring that your packs are rarely ever confiscated. How exciting!
6. Amsterdam Marijuana Seeds – Best Online Seed Banks Reputation
- Location: Amsterdam, The Netherlands
- Ships to: U.S., Canada, U.K., Most of Europe, Australia
- Shipping time to the USA: Estimated within 31 business days
- Free US stealth shipping
- Established 1996
- Free seeds with every order
- Multiple forms of payment, including cryptocurrency & wire transfer
- Longer than average wait time
Amsterdam Marijuana Seeds is one of the oldest companies and one of the first seed banks to gain popularity online. AMS is also one of the most generous companies, giving away free seeds with every order, or 3-10 extra seeds depending on how much you spend.
The company has also started shipping to Australia again, after a brief hiatus.
Try Amsterdam Marijuana Seeds for the free gifts and keep coming back for its reputable seed bank brand, and from the city that started the whole craze. As a wise stoner in a pulpy black suit once said, “You’ll dig it the most.”
7. Rocket Seeds – Fastest Delivery for Cannabis Seed Banks
- Location: The Bronx, NY, USA
- Ships to: Worldwide
- Shipping time to the USA: 5-7 business days
- Guaranteed delivery with Registered Tracking
- Germination guarantee
- Works with other seed banks to find rare items
- The fastest shipping
- Not a strong brand or unique savings
Rocket Seeds is a great place to find hard-to-find seeds, since the company works with multiple sources all over the world, including other seed banks. In fact, they often crossover with competitors like Crop King Seeds, Mary Jane’s Garden, and Sunwest Genetics.
The handshake agreement also means their prices are comparable to those companies and they won’t offer much in the way of unique discounts. Still, if you want a company based in the United States, and one that’s attentive to your unique requests, you can’t do better or do it faster.
They call it Rocket Seeds for a reason – they have fast US shipping.
8. Beaver Seeds – Best Seeds Bank Customer Support
- Location: Vancouver, British Columbia, Canada
- Ships to: Worldwide
- Shipping time to the USA: 7-25 days
- Free shipping
- Founded 2009
- Guaranteed delivery
- Accepts multiple forms of payment (inc. Bitcoin & cash)
- Not too many discounts
Beaver Seeds is a flexible seed bank all around, from their methods of payments, to free shipping, and guaranteed delivery, with paid tracking. The germination rate is guaranteed and all shipping is discreet.
Shipping time is 7-25 days which means it could be there quickly – as the company implies their delivery time is better than average, or there could be instances where the package is late.
Overall, what we liked about Beaver Seeds was the customer service telephone line, which is operated 24-7 and is even linked to a US location. When you’re nervously waiting for cannabis seeds to be shipped in the mail, having customer support to speak to is really helpful.
9. Quebec Cannabis Seeds – Most Popular Cannabis Seeds Packs
- Location: Vancouver, British Columbia, Canada
- Ships to: Worldwide
- Shipping time to the USA: Up to 2 weeks
- Guaranteed germination, 80% success rate
- Founded 2013
- Partners with Canada Grow Supplies for growing supplies
- Very potent THC and CBD strains
- No physical address provided
Quebec Cannabis Seeds stands by the quality of its seeds with a germination guarantee and assurance of expert packaging – the likes of which keeps the seeds fresh while hiding them in a DVD or card, for example.
Shipping time to the U.S. was also better than average, being about 14 days.
The company sold a number of bulk & mix packages and packs of 100, which are shipped discreetly and spread across a few packages. The most interesting aspect is the company’s Limited Edition line, which lets you buy rare marijuana seeds while they stay in supply.
Quebec Cannabis Seeds was founded in 2013, but still claims to have 15 years of experience in marijuana seed retail.
10. Marijuana Seeds NL – Best Free Seeds Deal
- Location: London, U.K. (surprisingly)
- Ships to: Worldwide
- Shipping time to the USA: 6-25 working days
- Started in 1999, the first online seed bank!
- Loyalty program that gives credits back for purchases
- Lower price than average
- Good deals on shipping
- Stealth shipping costs extra
While Marijuana Seeds NL isn’t the oldest seed bank brand, it is arguably the first successful marijuana seed bank, and with a name that is still trusted today.
Though the site is registered in The Netherlands, the company is actually based in the U.K. Customers can expect a rewards program, multiple payment options (with discounts for Bitcoin and wire transfers), and free seeds.
Buyers get 2 free feminized seeds with every order, 2 free auto-flowering seeds for orders over $75, and 4 feminized / 3 auto flower seeds for free when spending over $140.
You can also get free basic stealth shipping or discounted guaranteed delivery free shipping when ordering packs of seeds. Suffice it to say that you’ll have plenty of cannabis seeds to go around.
11. MaryJanesGarden – Easy Way to Order Cannabis Seeds Online
- Location: Vancouver, British Columbia, Canada
- Ships to: Worldwide
- Shipping time to the USA: Same day shipping, 1-3 weeks delivery
- Guaranteed delivery with tracking
- Established 2003
- Only the best seeds are sent
- Multiple payment options including Bitcoin and Paypal
- No wire transfers
Mary Jane’s Garden may seem new but they’ve been selling seeds online since 2003, with a higher than average 90% successful delivery rate.
The company also boasts about their highest quality seeds, using the best production process, and the strictest quality control procedures on the market.
The company also has one of the fastest delivery dates for U.S. residents, within 3 weeks, but oftentimes within 1 week because of the close proximity.
The company even has an added customer support line, so you can always chat with a team member if something happens to go wrong.
12. Sonoma Seeds – Most Promising New Seeds Bank
- Location: Vancouver, British Columbia, Canada
- Ships to: Worldwide
- Shipping time to the USA: 7-14 days
- Guaranteed germination
- Telephone support line
- 500+ strains, a high variety
- Multiple payment options inc. Bitcoin & cash
- Pricey shipping
- Average seeds price
- New company, founded 2019
Sonoma Seeds is admirable, simply because they ship anywhere, even though they can’t support every payment method. Still, Bitcoin is accepted and even cash through the mail, which means after payment is received, you get your seeds within 2 weeks.
That’s about as discreet as you can get.
Shipping is quick because of the proximity to the US and many different strains have been collected from all over the world. But Sonoma Seeds’ fast shipping to the U.S. is what impressed us the most… a promising company to watch.
FAQs About Buying Cannabis Seeds
If you’re curious about the logistics of buying cannabis seeds online, we have answers!
Are there any weed banks in the United States?
While many companies do seem to be a Canadian seed bank store, I Love Growing Marijuana and Rocket Seeds are both based in the United States and have a reputation for high-quality seeds.
As a result, their shipping to the US tends to be pretty fast (1-2 weeks or less).
Is it legal to buy cannabis seeds in any state?
Being in possession of cannabis seeds is not illegal, since they could be bought for collectible or research purposes. However, there are some complicated federal and state laws that might result in seed confiscation, or very rarely, some legal trouble.
Cannabis remains illegal at the federal level but legal in a number of U.S. states. No wonder all seed banks use stealth shipping to avoid legal hassles and confiscation.
What’s the safest way to pay for weed seeds?
Bitcoin and other cryptocurrencies are the safest way to pay, since there would be no official record of you buying it, besides records maintained by the cryptocurrency wallet provider.
However, paying by cash or money order is also safe, generally speaking.
Are online seed banks legit?
Practically all the seed banks we reviewed are legitimate, have great to good customer reviews, and have been established for a few years – or in some cases, over 20 years.
Some online seed banks might not be legitimate, but the ones in this article are.
Do all reputable seed banks offer international shipping?
No, some seed banks have temporarily halted international shipping because of COVID, while others choose to only ship to the U.K., Europe, U.S. Australia, and New Zealand in order to avoid legal problems with countries with stricter cannabis laws.
Always check that your cannabis seed bank ships to your country before you buy weed seeds online.
Do all marijuana seed banks have multiple payment methods?
No, most companies stick to credit cards, Paypal, bank wire transfers, and other electronic funds transfer methods. Cryptocurrency usage is rising, however, as well as cash and money orders which are harder to trace.
Discretion is key when ordering marijuana seeds.
Is it safe to order seeds?
Generally yes, it is safe to order seeds online from reputable seed banks.
Stealth shipping involves sending seeds inside various “fake items”, like DVDs or Birthday Cards you didn’t order. Some companies constantly rotate their choice of gifts, in order not to alert delivery persons. The online seed bank also lists an alias name when charging your card or cryptocurrency account.
Sometimes seeds are confiscated, but that’s why most companies offer a delivery guarantee, with a paid tracking charge. Larger packs may also be separated into multiple packages arriving, since a large pack of pot seeds would be difficult to hide in one small gift item.
Remember you can also check online reviews of the best cannabis seed bank brands and which companies excelled at safety, shipping time, guaranteed products, and best of all, the quality of the seeds themselves.
Where to Buy Marijuana Seeds Online: The Takeaway
Our research found that I Love Growing Marijuana and Crop King Seeds were the best of the best weed seed bank stores, because of their germination and delivery guarantees, not to mention a wide variety of available strains.
ILGM also offered some cost-saving deals and gave away tons of help guides to help newcomers break into DIY marijuana plant growing.
Crop King Seeds and Seedsman both had an impressive number of strains and hard-to-find names for the experienced marijuana seeds connoisseur, with Seedsman boasting 1500+ marijuana strains.
The best weed seed sites should stand by their production processes. Anyone might be able to grow marijuana nowadays, thanks to autoflowers and feminized seeds, but not everyone can do it right.
We hope you find the perfect seed bank for your needs!
The news and editorial staffs of The Denver Post had no role in this post’s preparation.
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.