I agree with Daisy.
The old T&M germination database says:
21-90 days to germinate.
slow and irregular germination
best germn temp 55-65 F
use well-drained soil to germinate
Just Cover the seeds
Stratify: place the moistened seed in a refrigerator for 4-6 weeks
If there's no room for pots in your fridge, you can instead place the seeds on a moist coffee filter or paper towel in a baggie in the fridge for 20-90 days. Mostly-close the baggie and make sure it doesn't dry out.
After the first 3 weeks, check every few days to find any seeds that have germinated. Plant these shallowly into a pot.
Here is Tom Clothier's advice (try room temp first for 3-4 weeks, or a shorter, colder stratification period):
Lavandula angustifolia , laciniata, latifolia, and stoechas:
Sow at 20ºC (68ºF),
if no germination in 3-4 wks, move to -4 to +4ºC (24-39ºF) for 2-4 wks
