Your lavender seeds need refrigeration to mimic the winter they'd face in nature. This cold period wakes up seeds that otherwise stay stuck in their shells. Without those weeks in your fridge, most of your seeds will never sprout no matter how perfect your soil and light might be.
I've watched this play out in my own seed trays over many seasons. My refrigerated seeds push up strong sprouts within two weeks of planting. The seeds I skip the cold treatment on sit there for a month or more. Maybe one or two finally wake up, but most just rot away in the soil doing nothing.
The cold stratification purpose ties back to how lavender grows in the wild. Seeds fall to the ground each autumn and sit through winter in cold dirt. Spring warmth wakes them up to grow. Your fridge recreates this cycle in just a few weeks at home.
Breaking lavender seed dormancy requires cold temps to work on the seed's inner chemistry. Each seed contains natural blockers that stop growth until conditions are right. Cold breaks down these blockers over time. It also preps the tiny plant inside to burst out when warmth returns.
Research shows big gains from cold treatment. Without it, only 20-30% of your seeds will sprout. With proper stratification, that rate jumps to 80-90% instead. You get three to four times more plants just by using your fridge for a few weeks first.
Start your cold treatment by placing seeds on a damp paper towel. Fold the towel and slip it into a sealed plastic bag. Put the bag in your vegetable crisper where temps stay around 35-40°F (2-4°C) all the time. Leave your seeds there for 3-6 weeks depending on how patient you can be.
Check your seeds every week or so while they chill. You want the towel to stay moist but not dripping wet. Some seeds may start to show tiny white root tips near the end of the cold period. That's your sign they're ready to plant in soil and move to warmth.
After fridge time ends, plant your seeds in seed starting mix right away. Set your trays on a heat mat or in a warm spot around 70°F (21°C) for best results. Your properly stratified seeds should pop up within 14-21 days now that you've told them winter is over and it's time to start growing.
Read the full article: How to Grow Lavender From Seed Successfully
