Every grow starts the same way: convincing a seed it's spring. Germination needs exactly three things — moisture, warmth, and darkness. Get those right and a healthy seed pops in 2–5 days.
What you need
- Two clean plates
- Paper towels (plain, no lotion or prints)
- Distilled or filtered water, pH 6.0–6.5
- A warm spot: 21–26 °C (70–78 °F)
- Your seeds
The paper-towel method
- Soak (optional but useful for old or hard seeds). Drop seeds in a glass of room-temperature water for 12–18 hours, no longer. Seeds that sink are usually viable; floaters often still sprout, so don't toss them yet.
- Wet the towels. Fold a paper towel onto a plate, wet it thoroughly, then pour off standing water. Damp, not dripping.
- Place the seeds an inch apart, cover with a second damp towel, then invert the second plate on top to trap humidity and block light.
- Keep it warm. Top of a fridge, a seedling heat mat on low, or any spot that holds 21–26 °C. Below 20 °C germination slows to a crawl; above 30 °C you cook them.
- Check twice a day. Re-wet the towel if it's drying out. Most seeds show a white taproot within 48–120 hours.
Other germination methods
Direct sow — plant the seed 1 cm deep straight into moist starting medium. No transplant shock, no fragile taproot to handle. The trade-off: you can't see whether the seed has popped, so you wait longer before knowing. Good for fresh feminized seeds with high germination rates.
Water glass only — drop seeds in water and wait until you see a taproot emerge (usually 24–72 hours). Simple, but seeds left too long in standing water drown. Don't exceed 24 hours in the glass; switch to paper towel if no taproot yet.
Rapid Rooters / Jiffy pellets — pre-moistened plugs designed for seed starting. Poke a hole, drop the seed in pointed end down, and keep the plug moist. Convenient, but more expensive per seed.
For a detailed comparison of starting media, see the seed starting media guide.
Planting the sprout
When the taproot is 1–2 cm long, plant it. Longer roots tangle in the towel and snap — and a snapped taproot is usually fatal.
- Make a 1 cm hole in moist (not soaked) starting medium
- Place the seed taproot down, cover loosely
- Mist the surface; don't compact the soil
- First light: gentle — a T5 or LED at 50% power, 45–60 cm away
The seedling should break the surface within 24–72 hours. If you see a bent stem pushing up but the seed shell is still attached ("helmet head"), wait a day — most shed it naturally. If it's still stuck, mist and gently work it off with tweezers.
The two mistakes that kill most seeds
Drowning. A seed that sits in standing water runs out of oxygen. Damp towel, drained plate — that's the whole trick.
Fiddling. Checking is fine; handling is not. Every time you pick the seed up you risk snapping the root. Use clean tweezers exactly once: when you plant it.
Troubleshooting slow or failed germination
No taproot after 5 days: the seed may be dead, old, or dormant. Try scoring the shell lightly with fine sandpaper (scarification) and re-soaking for 12 hours. If nothing happens by day 7, start a new seed.
Taproot emerged but seedling never surfaces: usually planted too deep (more than 2 cm) or the medium dried out. Keep the top layer consistently moist — not soaked, just damp.
Seedling comes up white or very pale: it hasn't seen light yet or the shell is blocking the cotyledons. Make sure your light is on (18/6 cycle) and the seed shell is off.
Germination rates drop with seed age. Fresh seeds from a reputable breeder run 90%+; a five-year-old bag find might give you one in four. Plant extras accordingly.
Once the first round leaves (cotyledons) open, you have a seedling — and a new set of rules. See the seedling care guide for the fragile first two weeks.