Trilliums is a fascinating group of woodland plants and in my garden I have a healthy 10 year old, big clump of Trillium cuneatum under my tall cedar tree.…
They are fully to frost hardy, and will prefer a moist soil with ample water and shade.
You will find that results from seed will take a very long time. Sow in the autumn for germination in the second spring. Or divide mature plants in the summer.