I don't know, but I decided to try pre-germinating my Purple Passion Asparagus seeds I collected this spring from last year's dried stalks.
Soaked overnight in filtered water, then rinsed and drained over a folded paper towel on teacup saucer. Kept in east facing sunny window by day, room temperature at night, rinsed/drained twice a day. They started to germinate in one week.
I sowed some of the germinated seeds in a flower pot of 1/2 potting soil 1/2 sand, and sowed the extra seeds outside.