Vernalization

Vernalization is adjusting seeds to a winter environment, which can be useful for seeds that require a cold period before sprouting.  With the seeds I have, only the cleome benefits significantly from it, while the Easter eggplant finds it mildly helpful but not necessary.  However, since I have to vernalize the cleome, the Easter eggplant goes along for the ride.

The process is very simple.  Place the seeds in their starter trays and moisten them just as you would when sprouting any other seed.  The place the starter tray in a cool to cold environment, by preference one that doesn't regularly freeze.  I use the garage and keep the trays toward the interior wall.  Temperatures may occasionally drop below freezing, but generally stay around 32.

The refrigerator can be another good place to vernalize seeds if a garage isn't handy, and you can put them in a damp, covered glass.

Vernalization generally requires about six weeks in the colder environment.  Post that period, remove whenever you like and grow normally.

Any seed from any tropical or sub-tropical plant will never require vernalization and at best won't benefit from it.  Marigolds, zinnia, salvia, celosia, and most other common summer garden plants don't require vernalization and may not survive in low temperatures.