Trilliums are very common native plants here in the PNW and they often grow naturally in woodsy rural areas. But they are commonly sold in garden centers as well and all different varieties and colors. These are not wild harvested plants but commercially grown specimens and are adaptable to any shady garden situation. Just an update, but my trillium Volcano discussed above made its move without issue and thrived in my friend's garden for several years before he graciously shared a chunk with another friend. And that plant took transplanting well and has thrived also. Now that I have moved from a full sun beach location to one where I am more shelterer by trees and with considerable shade, a chunk of that plant is coming home to take up residence with me again!! So three moves and at least one division did no harm at all.

Trillium seeds have a seedcoat containing germination inhibitors. ANts usaull eat the coat and thus disperse the seeds. Trillium seeds also require double dormancy (two 3 month cold periods w/ a warm period between) to germinate. The first cold period is required to break "radicle dormancy" and the second is needed to break "epicotyl dormancy". Fresh seed (not dried) is best. Mine have spred nicely both in clumps and seedlings sprouting up. I take the seed before the ants get them and kind of squeeze them out of their seedcoat and into the ground. Takes around 4 yrs from seedling to flower for me.

Not usually but it depends a fair bit on the type of trillium and the conditions they're grown in. The big white grandiflorums are the fastest spreaders I think. In my experience they grow best in soil that is a bit moist in spring - but not wet - and then it doesn't seem to matter if it dries out later in the summer after they're dormant. They also seem to prefer lots of leaf litter and organic matter from letting plants die back in the fall and undisturbed soil - i.e. don't cultivate around them if at all possible. And decduous shade of course. When we bought this house in 1999, we discovered the following spring that we had a few small clumps of T. grandiflorum that were being engulfed by pachysandra. We cleared out the pachysandra and planted things like columbine and other herbaceous woodland plants and let all the ash, oak and pine needles stay on the ground and did no spring or fall clean-up in that area. This is what it looked like this past week:

Nope, but Id like to see yours.