How Long Do Cannabis Seeds Last?

Cannabis seeds are a grower's most valuable asset, but their viability declines over time. Whether you're saving seeds for future grows or stocking up on your favourite strains, it's really important to understand how long cannabis seeds last and how to store them properly.

At Oaseeds, we prioritise freshness and quality, ensuring that all our seeds are less than one year old. As seeds approach the one-year mark, we move them to our Outlet section which is where you can find discounted seeds that are still viable but nearing the end of their peak germination period.

So, how long do cannabis seeds last, and how can you keep them fresh for as long as possible? Let's find out.

How Long Are Cannabis Seeds Stay Viable?

With proper storage, cannabis seeds can remain viable for several years. But, at the same time, their germination rate decreases over time.

So, here's a general guide to how long cannabis seeds last under different conditions:

• Stored in a cool, dark place (room temperature): Up to 1-2 years
• Stored in a refrigerator: Up to 5 years or more
• Stored in a freezer (long-term storage): Up to 10 years, but with reduced success rates

At Oaseeds, we make sure that all our seeds are stored in a controlled, refrigerated environment to maintain their freshness and high germination potential.

Factors That Affect Seed Longevity

The lifespan of cannabis seeds depends on how they are stored.

Here are the key factors that impact seed viability:

1. Temperature

Seeds last longer when kept in a stable, cool environment. Fluctuations in temperature can cause moisture buildup, leading to deterioration. The ideal temperature range for cannabis seed storage is 4-8°C (the temperature of a refrigerator).

2. Humidity

Moisture is the biggest threat to seed longevity. High humidity can trigger premature germination or mould growth, while overly dry conditions can make seeds brittle. The ideal humidity level for storing cannabis seeds is 20-30%.

3. Light Exposure

Seeds should be kept in complete darkness, because UV light can degrade their internal structure. This is why professional seed banks store seeds in opaque, airtight containers.

4. Oxygen Levels

While seeds need some oxygen, excessive air exposure can cause them to age faster. Vacuum-sealed or airtight containers help extend shelf life by reducing oxidation.

How to Store Cannabis Seeds for Maximum Freshness

If you want your seeds to last as long as possible, follow these storage tips:

1. Use an airtight container: Glass jars, vacuum-sealed bags, or vials with moisture-absorbing packs work best.
2. Store in a refrigerator: Keep your seeds in the fridge at a constant temperature to prevent fluctuations.
3. Avoid opening the container too often: Frequent exposure to air, light, and moisture can reduce viability.
4. Label your seeds with the date of purchase: This helps you track their age and prioritise using fresher seeds first.
5. Keep seeds in a dark place: Even if stored outside a fridge, they should be kept in a drawer, cupboard, or other light-proof location.

At Oaseeds, we store all our seeds in a refrigerated environment, ensuring they remain fresh and viable for as long as possible.

Signs That a Cannabis Seed is No Longer Viable

Even with proper storage, cannabis seeds can eventually lose their ability to germinate.

Here are some signs that a seed may no longer be viable:

• It feels soft or squishy: Fresh seeds are firm and hard, while old seeds can become fragile or spongy.
• It has visible cracks: A cracked seed shell indicates it has dried out too much and is unlikely to germinate.
• It is discoloured: Healthy seeds are normally dark brown with a brindle pattern. Seeds that turn pale, grey, or white may have lost their viability.
• It floats in water: Viable seeds tend to sink in a glass of water, while old or hollow seeds often float.

If your seeds are over a year old, it might be time to replace them with fresher ones for better germination success.

Get Great Deals in Our Outlet Section!

At Oaseeds, we guarantee that all our seeds are less than one year old, ensuring they have high germination rates.

However, as seeds approach one year of age, we move them to our Outlet section, where you can get discounted seeds that are still viable but nearing the end of their peak period.

This is a fantastic way to buy quality cannabis seeds at reduced prices, especially for growers who want to experiment with different strains without spending too much.

FAQs On How Long Cannabis Seeds Last

1. Can cannabis seeds last forever?

No, cannabis seeds have a limited lifespan. With proper storage, they can remain viable for up to 5 years, but their germination rate does tend to decline over time.

2. Should I store cannabis seeds in the fridge or freezer?

The fridge is the best option for long-term storage (up to 5 years). While some growers store seeds in the freezer, freezing can damage delicate cells inside the seed, making germination less reliable.

3. Do cannabis seeds go bad?

Yes, seeds can become too old to germinate, especially if stored in warm, humid or bright conditions. Fresh seeds (under a year old) have the highest success rates.

4. How can I tell if a cannabis seed is still good?

A viable seed should be dark brown, firm, and uncracked. If a seed floats in water, feels soft or has visible damage, it may no longer be viable.

5. Where can I buy fresh cannabis seeds?

At Oaseeds, we only sell fresh, high-quality seeds that are less than a year old.

How Environmental Factors Impact Cannabis Seed Viability

The longevity of cannabis seeds depends heavily on environmental factors. Exposure to fluctuating temperatures, moisture, light and air can significantly reduce their lifespan.

Temperature fluctuations are particularly damaging. If seeds are repeatedly exposed to warm and cool cycles, condensation can form inside the seed, leading to premature germination or rot. Keeping seeds in a consistent, cool environment, like a refrigerator set between 4-8°C, prevents this issue.

Humidity levels must also be carefully controlled. Excess moisture can lead to fungal growth or germination failure, while overly dry conditions can cause seeds to become brittle and lifeless. The optimal humidity for seed storage is around 20-30%.

Finally, oxygen exposure plays a role in seed degradation. While some airflow is necessary, too much oxygen can accelerate the aging process. This is why vacuum-sealed containers or airtight jars are recommended for long-term storage.

Common Mistakes That Reduce Seed Longevity

Many growers unknowingly reduce the lifespan of their seeds through improper handling and storage. One of the most common mistakes is storing seeds in plastic bags or containers that are not airtight, which allows air, moisture, and light to seep in, accelerating degradation.

Another mistake is handling seeds with bare hands. The natural oils from your fingers can create a thin film of moisture, leading to potential mould issues. Always use tweezers or wear gloves when handling cannabis seeds.

Some growers attempt to store seeds in paper envelopes or leave them in the original packaging. While these options may work for short-term storage, they don't provide adequate protection for long-term viability.

Lastly, frequently opening and closing the seed container introduces temperature changes and humidity fluctuations. For maximum longevity, store seeds in a stable, undisturbed environment and only open the container when necessary.

Closing Thought On How Long Cannabis Seeds Last

So, how long do cannabis seeds last? Well, with proper storage, they can remain viable for several years, but the best germination rates come from fresh seeds under one year old.

Storing seeds in a cool, dark, airtight environment (preferably in a refrigerator) will help extend their lifespan.

At Oaseeds, we ensure that all our seeds are fresh and properly stored. When seeds approach one year old, we move them to our Outlet section, where growers can get quality seeds at discounted prices.

Want to stock up on fresh cannabis seeds? Browse our collection today and secure the best genetics for your next grow!