Plant Trilliums in spring flowering beds that are fully or partially shaded. Be certain about where you want to plant them as once they are established, moving them is hard on the plant.
Mix the rich organic matter into the soil. Soil should be rich and loamy for the best growing conditions for Trilliums.
Dig a hole as deep as the pot the Trillium plant currently lives in.
Mix the soil you remove from the hole with more of the rich organic matter.
Mix some of the rich organic matter into the soil at the bottom of the hole.
Place the Trillium plant into the hole. Make sure that the base of the plant is at or just below the level of the soil.
Fill in the hole with the soil you removed.
Tamp the soil down around the base of the Trillium plant.
Water the Trillium plant thoroughly.
Repeat, creating a fairly dense carpet of Trillium plants in an area, as they would grow in the woods. Leave room for them to propagate themselves over time.