Based on field observation, we suspect that heavy leaf cover would not be ideal. We usually see this plant growing in areas where leaves have not formed a dense layer. Squaw weed or roundleaf groundsel seems to be fairly evergreen and likely needs some light, even over winter. A solid layer of tree leaves could smother the plants. You could remove the leaves in the fall with a leaf blower or lawn mower that is set to mow fairly high. However, other wildlife depend on that dense leaf litter. For example, luna moths overwinter in cocoon form in those leaves. You would be ahead to choose a different plant, such as wild ginger, bluebells, goldenseal, solomon's seal, or wild geranium, if your site is going to produce a heavy layer of leaves.