Bluebell
My non-scientific experiments with tomato seed germination are these:
1. Trays placed on top of newspaper placed on an outdoor gas boiler germinate seeds 100% within 4 days in January and February.
2. Modules kept at 20C indoors in an interior cupboard in March take 7 days to germinate.
As I grow using biodynamic calendars, as long as seeds are through within 9/10 days all is well, as I tend to transplant seedlings into 5cm pots on a fruit day at that stage and then grow as normal.
Absolutely saturated subsoil, topsoil left dry and the heat of a gas boiler from underneath has been my go-to method the past 2 years though!
It has the advantage that the sole requirement for germination is an old ice cream tub. And a covering of cling film to retain the moisture.
I’ve found germinating with the moon in Leo the past two years has led to perfect 100% germination and very healthy plants down the line. But none of it has been rigorous science……