Understanding Cannabis Seed Viability and Storage
Cannabis seed viability all comes down to how you store them. Treat your seeds well and they’ll last years. Leave them sitting in heat, light, or moisture and they’ll age faster than you’d expect.
The truth is: Age matters far less than storage conditions.
Fresh seeds from reputable seed banks generally perform best because they’re kept cool, dry, and stable from the moment they’re harvested.
If you’re starting a collection or want to protect the strains you’ve worked hard to source, it pays to understand what keeps a seed alive — and what slowly kills it.
If you’re building a seed collection, start here: our complete guide to buying cannabis seeds in Australia
Real-World Seed Longevity: What I’ve Seen First-Hand
After testing batches ranging from fresh harvest to 5+ years old, I can tell you this with confidence:
I’ve seen five-year-old seeds pop at 90%+.
I’ve seen six-month-old seeds fail completely.
The difference isn’t the calendar — it’s how they were stored.
Seeds are living organisms in dormancy. They’re asleep, not dead. While they wait, three things slowly chip away at their viability:
- Heat
- Light
- Moisture
Control these, and your seeds can outlast your expectations. Ignore them, and you shorten their lifespan dramatically.
What Affects How Long Cannabis Seeds Stay Viable?
1. Temperature (The Big One)
Heat ages seeds quickly. As a rough rule of thumb:
- Every 5°C rise in storage temperature roughly halves a seed’s life.
- At 25°C, seeds might stay viable 1–2 years.
- At 5–10°C, seeds can last 5+ years with minimal decline.
This is why all Sacred Seeds inventory is stored in climate-controlled conditions at 5–10°C. It protects not just this month’s stock, but the batches that sit with us a little longer.
In Australia, a “cool cupboard” in summer can still hit 30°C — and at those temps seeds age fast.
If you’re storing long-term, the fridge (not freezer) is your best bet.
2. Moisture (The Silent Killer)
Humidity controls whether seeds stay dormant or begin to “wake up.”
Above 60% humidity: seeds start metabolic activity → they burn energy → mould risk skyrockets
Below 20%: seeds can dry out too far and become brittle
The sweet spot is 20–40% RH.
I use airtight glass containers with silica gel inside. Simple and effective.
3. Light Exposure
UV light breaks down the protective compounds in seed shells and speeds up degradation.
That’s why:
- we store seeds in opaque containers
- breeders use amber tubes or foil-lined packs
- you should never keep seeds in clear bags on a sunny shelf
Keep seeds in complete darkness for best longevity.
4. Genetics & Initial Quality
A seed that’s properly bred, harvested at full maturity, and dried correctly will outlive a rushed or immature seed every time.
Part of why we’re selective with breeder partnerships is because longevity starts before the seed ever reaches your hands.
How Should I Store Cannabis Seeds for Maximum Shelf Life?
These are the exact guidelines I use personally and professionally:
– Airtight Containers
Glass jars with rubber seals, vacuum bags, or quality plastic containers all work.
The goal: no temperature swings, no moisture fluctuations.
– Cool, Dark Location
Long-term (1+ years): refrigerator, ideally the vegetable crisper
Short-term (under 6 months): a consistently cool, dark cupboard is fine
– Avoid Freeze–Thaw Cycles
Freezing can extend life if done perfectly — but any thawing introduces moisture stress.
If you freeze seeds, they stay frozen until use.
– Label Everything
Strain name + storage date.
Seeds all look identical after six months.
– Keep Original Breeder Packaging
It adds another moisture/light barrier.
Store it inside your airtight container for double protection.
– Test Older Batches
If you’re working with seeds 2+ years old, germinate one tester first.
JASON’S QUICK STORAGE CHECKLIST
✅ Temperature: 5-10°C for long-term (refrigerator), 15-20°C for short-term (cool cupboard)
✅ Humidity: 20-40% relative humidity (use silica gel packets)
✅ Light: Complete darkness (opaque containers)
✅ Container: Airtight glass or quality plastic
✅ Location: Refrigerator vegetable drawer or cool, dark cupboard
✅ Labels: Strain name and storage date on every container
Sacred Seeds Storage Guarantee
At Sacred Seeds, every pack we ship comes from climate-controlled storage and double-checked stock cycles. Your seeds arrive fresh — but once they’re in your hands, their shelf life depends on how you store them.
Follow these guidelines and your collection can stay viable for years.
Frequently Asked Questions
Can cannabis seeds go bad?
Yes, cannabis seeds lose viability over time, especially when exposed to heat, light, or moisture. Properly stored seeds can last 5+ years, but seeds stored in poor conditions (hot garage, clear plastic bags, high humidity) can lose viability within 6-12 months. Signs of bad seeds include pale color, soft or cracked shells, and failure to germinate.
How long do cannabis seeds last in the fridge?
Cannabis seeds stored in a refrigerator (5-10°C) in airtight containers with silica gel can last 5-10 years with minimal loss of germination rates. The cool, stable temperature dramatically slows seed aging. Store seeds in the vegetable crisper drawer to avoid temperature fluctuations from frequent door opening.
Should I freeze cannabis seeds for long-term storage?
Freezing can extend seed life beyond 10 years, but only if done correctly. Seeds must be completely dry (below 8% moisture content) and sealed airtight. Never freeze and thaw repeatedly—each cycle damages seeds. For most collectors, refrigerator storage (not freezing) is safer and sufficient for 5-10 year storage.
How do I know if old cannabis seeds are still good?
Viable seeds are firm, dark brown or tan with tiger stripes, and have intact shells. Green, soft, or cracked seeds are likely dead. The only reliable test is germination—try germinating 1-2 seeds from an old batch before committing to a full grow. Seeds stored properly can surprise you with high germination rates even after several years.
Do feminised seeds last as long as regular seeds?
Yes, feminised seeds have the same shelf life as regular seeds when stored properly. The feminisation process doesn’t affect seed longevity—storage conditions (temperature, humidity, light) are what determine how long any cannabis seed lasts, regardless of whether it’s feminised, regular, or autoflower.
Can I store different cannabis strains together?
Yes, you can store multiple strains in the same container or refrigerator as long as each strain is in its own sealed package or small jar. Keep strains separated and clearly labeled to avoid mixing them up. The storage conditions (temperature, humidity, darkness) are the same for all cannabis seeds regardless of strain.
What’s the best container for storing cannabis seeds?
Small glass jars with rubber-sealed lids (like spice jars or mason jars) are ideal. Add one small silica gel packet per jar to control humidity. Alternatively, vacuum-sealed bags or quality plastic containers with tight lids work well. Avoid clear containers—use opaque or amber glass to block light.
How long do cannabis seeds last in their original packaging?
In original breeder packaging stored in cool, dark conditions, cannabis seeds typically last 1-2 years with good germination rates. However, original packaging alone doesn’t provide optimal long-term storage. For best results, store the original packaging inside an airtight container with silica gel in a refrigerator.