Most of Michigan has a USDA Plant Hardiness Zone rating of five, with some southern corners falling in Zone six. This rating means that Michigan is within the climate range for most types of peonies, but some tree varieties will need winter protection to bloom regularly. Peonies are perennial, so they will return year after year, and as long as your peonies are planted in an appropriate location they will require very little maintenance. Simply choose a sunny location with rich, well-drained soil and enjoy your flowers for years to come.
Prepare the soil with compost before you plant a new peony bush. Peonies should be planted in the fall, in September or early October. Mixing compost into your soil will ensure the soil is rich and ready to support the peonies, which require fertile soil. Choose a location with full sun and good soil drainage (water drainage is key to a healthy peony plant, because standing water will cause root rot and kill the peonies).
Plant your peonies in the prepared soil, paying careful attention to the planting depth. Tree peonies are usually marked at the nursery so you know how deep to plant them, but herbaceous or intersectional peonies are not marked. Peonies are usually sold or transported as a clump of thick roots, and on top of the roots will be several small, pinkish crown buds. Use a garden spade to dig a hole large enough to accommodate the root clump, and plant the peonies so that the highest crown bud is about two inches below the dirt (the entire root clump will be covered with soil). Water your newly planted peonies thoroughly.
Water peonies when the dirt is dry, being careful not to over-water the plants. Peonies will tolerate drought, but they will not tolerate muddy soil. Usually rainwater will be sufficient, but if rain is scarce and the soil is very dry you should supplement the rainwater every week or so. Stop watering when the peonies are dormant, beginning in late fall until the peonies show signs of new growth in the spring.
Resist the urge to cut the flowers off young peony plants. Harvesting too many flowers of plants that are less than five years old will stunt the plant's growth, because cutting the flower stem also deprives the plant of its leaves. Leave flowers intact for the first five years, and only harvest 50 percent of the blooms after the plant is mature.
Add a layer of organic mulch around your plants each spring to help retain moisture and discourage weed growth. Keep the mulch layer between one and two inches thick.
Remove the leaves and stems form your plants in the late fall to prepare the peonies for winter. Use sharp garden shears to trim stems on herbaceous and intersectional (bush) peonies to within an inch of the ground, and discard the old stems. Tree varieties will drop their leaves in the fall, but should be wrapped with white tree guards to protect them from cold wind and ice. You can buy tree guards at garden or hardware stores.