Fresh seed produce most reliable germination. Old and dried seed may produce some seedlings, but the germination percentage will probably be low or none and takes longer. Trillium seed require a double dormancy, a warm-cold-warm period and a second warm-cold-warm period. If seed are planted and left outdoors, they usually begin germination during the second year.
Select a pot or tray large enough to accomodate the quantity of seed you have, without crowding them. If the pot is a reused one, sterilize it by washing in a solution of one part household chlorine bleach and nine parts water.
Use a soilless mix, or better, a seed starting mix, which is a finer texture. Moisten the mixture before planting the seed. Be sure the pot or tray has good drainage.
Place the seed on the moistened mix, keeping them separated as much as possible. I use tweezers or plastic gloves to avoid contact with the seed, which may contaminate them.
Cover the seed with about ½" of moistened potting mix and then ½" or less of washed coarse sand. This prevents moss and algae from growing on the surface. Cover the pot with a fine metal screen mesh to prevent rodent damage.
You may plunge the pot in sand or soil, up to just below the rim and cover with leaves or conifer needles during the winter, to conserve moisture. Remove the mulch in the spring.
Check frequently during dry periods for soil moisture and do not allow the soil to become dry.
When seed begin to germinate, you will see a single leaf-like form (cotyledon) emerge. It usually remains for the first year and true leaves will emerge the following year.
Depending upon the species, it will usually require 3-5 years before flowering occurs. Some say much longer.
To prevent damping-off, drench the soil with garlic water after planting.
(one or two cloves of minced garlic in a pint of water, let steep for a few hours).
If you use sterilized soil and pot and good sanitation practice, that is usually unnecessary.
After true leaves appear, if you wish to fertilize them, use a slow release general purpose fertilizer, such as 14-14-14, in the spring.
I usually wait until they attain a height of several inches before removing them from the pots and transplanting in the garden.
Hope other members with experience growing Trillium from seed will chime in with their process. Always helps to have different perspectives.
Rb

Rb,

Doesn't trillium seed covering have a germination inhibitor of some kind? If I remember correctly ants disperse the seed by carrying them off and eating the covering. Could be wrong 'bout this. W/ my plants I squeeze the fresh seeds out of the seedcoat and right into the ground. Hard to tell the germination rate but I have tons of little guys coming up from doing this.

kwoods....
The coating found on Trillium (and other Genera) seed is an elaiosome (Oil+body) and is rich in fatty-acids & protein. It is designed to attract ants for seed dispersal(myrmecochory). Ants carry the coated seed to their nests and feed the elaiosome to their larvae. The remaining seed is carried to their waste disposal area, where decaying matter aids in germination.
Elaiosome loses it's attraction to ants as soon as it begins to decay, a matter of a few hours in high temperatures, and they often abandon the seed before they reach the nest.
It does not contain inhibitors or enhancements, but some limited tests indicate that removing the elaiosome on freshly collected seed or waiting 48+ hours after collecting the seed before planting, could produce a higher germination rate?
In my seed sowing experience, it usually takes that long for me to get around to planting them! :Rb

Razorback33,

Does it work to simulate the w-c-w sessions by putting the seed pots in the freezer or refrigerator for a few weeks then bringing them back out to a warm area? Does that speed things up any at all?

Thanks!
VG

I wouldn't use the freezer, but the vegetable drawers in the refrigerator will be OK (35-40°F + humidity). Be sure that there are no apples in close proximity (when ripening, they emit ethylene gas).
Allow about 90+ days for each temperature cycle. After the second chill period, you should begin to see a radicle appear.
Good luck! :>)
Rb

Thanks! I'm going to try half my seed outside and half inside using the method you suggested.
VG