By Laurie Zitterkopf, Nebraska Extension Master Gardener
Fall is a great time to plant trees. Tree islands can be small, such as a few perennials or groundcovers in the mulch ring around the tree. But generally speaking, the larger the landscape island is, the more benefits it provides. Good companion plants include shrubs of all kinds, as well as many perennials, ornamental grasses, and various groundcovers. When the trees are young, the companion plants should be sun-loving. But as the trees grow, the companion plantings can transition to more shade-tolerant types.