Why Aren’t My Cannabis Seeds Germinating?

Introduction to Germinating Cannabis Seeds

• Germinating cannabis seeds is the first step in growing a healthy cannabis plant, requiring careful attention to detail and the right conditions
• Understanding the process of germinating cannabis seeds helps ensure successful germination and a strong start for your cannabis plants
• Viable cannabis seeds germinate easily under the right conditions, including moisture, warmth, and darkness
• The germination process typically takes a few days to a week, but can take up to 14 days in some cases
• If you’re new to growing, start here: our complete guide to buying cannabis seeds in Australia.

After testing thousands of seed batches over the years, I can tell you that germination failures usually come down to three things: temperature, moisture, or seed age. The good news? Most germination problems are completely preventable once you understand what seeds actually need to sprout.

Seeds are living organisms with specific environmental requirements. When those needs aren’t met, they simply won’t germinate. Let me walk you through the most common issues I see and exactly how to fix them.

What Causes Cannabis Seeds to Fail During Germination?

Temperature problems are the number one culprit. Cannabis seeds need consistent warmth to germinate—ideally between 22-25°C (72-77°F). I learned this the hard way during our travels through Nepal, where I watched traditional farmers place seeds in warm, dark spots near cooking fires. They understood intuitively what science confirms: seeds won’t crack open in cold conditions.

In Australia, especially during winter months, many collectors make the mistake of germinating seeds in cold rooms or garages. Even if the daytime temperature seems fine, overnight drops can halt the germination process entirely. I always recommend using a seedling heat mat or placing seeds on top of a warm appliance like a refrigerator or WiFi router. Consistent warmth is more important than high heat.

Moisture balance is equally critical. Seeds need to stay consistently moist (not soaking wet, not dry) throughout germination. 

The paper towel method works well, but only if you check moisture levels twice daily. I’ve seen countless seeds fail because the paper towel dried out overnight or, conversely, became waterlogged and caused the seeds to rot.

The principle is simple: gentle, consistent moisture without drowning the seed. If you’re using the paper towel method, the towel should feel like a wrung-out sponge—damp to the touch but not dripping.

Seed age and storage conditions matter more than most people realise. Fresh seeds from reputable sources like Sacred Seeds typically show 95%+ germination rates because they’ve been stored properly in climate-controlled conditions. But if seeds have been exposed to heat, light, or humidity fluctuations, their viability drops fast.

I test every batch that comes through our facility, and I can often predict germination rates just by examining the seeds visually. While it is true that some strains always produce more pale or smaller seeds, there is some truth to the idea that dark, firm seeds with intact shells almost always perform better. This is why we’re obsessive about storage—our seeds stay in airtight containers at controlled temperature and humidity until they ship to you.

How Can I Increase My Germination Success Rate?

Follow the proven paper towel method correctly. Place seeds between damp (not soaking) paper towels, put them in a sealed container or plastic bag, and keep them in a warm, dark place. Check twice daily—morning and evening—to ensure the towel stays moist. Most healthy seeds will crack open within 24-48 hours and show a white taproot within 2-5 days.

Don’t plant seeds too deep. When transferring germinated seeds to soil, plant them no deeper than 5-10mm. I’ve watched collectors bury seeds 2-3cm deep and wonder why nothing emerges. The seedling needs to reach light quickly, and deep planting exhausts its energy reserves before it breaks the surface.

Use quality water. Tap water with high chlorine or mineral content can inhibit germination. I use filtered or bottled water for the initial germination phase. It’s a small detail that makes a measurable difference, especially with sensitive genetics.

Be patient but realistic. Most cannabis seeds germinate within 2-5 days under ideal conditions, but some varieties (particularly older landrace genetics) can take 7-10 days. However, if you’ve seen no activity after 10 days with proper temperature and moisture, the seed likely isn’t viable.

Start with fresh, properly stored seeds. At Sacred Seeds, we stand behind our Quality Guarantee because we control every variable we can—from breeder selection to climate-controlled storage to shipping methods. But even the best seeds need the right conditions to germinate. Give them consistent warmth, gentle moisture, and a bit of patience, and you’ll see that white taproot emerge right on schedule.

Quick Germination Checklist:

✅ Temperature: 22-25°C consistently
✅ Moisture: Damp paper towel, check twice daily
✅ Depth: 5-10mm when planting
✅ Water: Filtered or bottled
✅ Patience: 2-5 days typical, up to 10 days for some strains
✅ Fresh seeds: From reputable sources with proper storage

Having germination issues with seeds from elsewhere? It might be time to start with fresh, properly stored genetics. Browse our full cannabis seed collection backed by our germination guarantee.

Frequently Asked Questions

How long should cannabis seeds take to germinate?

Most cannabis seeds germinate within 2-5 days under ideal conditions (22-25°C, consistent moisture). Some varieties, particularly landrace genetics, can take up to 7-10 days. If you see no activity after 10 days with proper temperature and moisture, the seed is likely not viable.

What temperature is best for germinating cannabis seeds?

The ideal temperature range is 22-25°C (72-77°F). Seeds need consistent warmth throughout the germination process. Use a seedling heat mat or place seeds on top of a warm appliance like a refrigerator to maintain steady temperature, especially during Australian winter months.

Should I soak cannabis seeds before germinating?

Soaking is optional. The paper towel method (seeds between damp paper towels in a sealed container) works reliably without pre-soaking. If you do soak, limit it to 12-24 hours in room temperature water. Over-soaking can drown seeds and cause rot.

Why are my seeds cracking but not sprouting?

If seeds crack open but don’t develop taproots, the issue is usually temperature (too cold) or the seed has exhausted its energy reserves. Ensure consistent warmth (22-25°C) and check that the paper towel stays damp but not waterlogged. Old or poorly stored seeds may crack but lack the vigor to sprout.

Can I germinate seeds directly in soil?

Yes, but the paper towel method gives you more control and visibility. If planting directly in soil, plant 5-10mm deep in pre-moistened soil, keep temperature at 22-25°C, and maintain consistent moisture. Direct soil germination works best with very fresh seeds.

How do I know if my cannabis seeds are still viable?

Viable seeds are typically dark brown or tan with tiger stripes, firm to the touch, and have intact shells. Pale, green, or cracked seeds rarely germinate. The float test (viable seeds sink, dead seeds float) is unreliable. The best indicator is purchasing from reputable sources with germination guarantees.

What’s the best water to use for germinating cannabis seeds?

Use filtered, bottled, or distilled water. Tap water with high chlorine or mineral content can inhibit germination. If using tap water, let it sit uncovered for 24 hours to allow chlorine to evaporate. Water should be room temperature (20-22°C).

Do cannabis seeds need light to germinate?

No. Cannabis seeds germinate best in darkness. Light is only needed once the seedling emerges from the soil. Keep germinating seeds in a dark, warm place (like a closed container or cupboard) until the taproot