Answer: When planting into sandy soil, you should first work in a layer of organic matter 3 to 6 inches thick. This will help the soil hold both moisture and nutrients. After planting, maintain a layer of organic mulch about three inches thick over the soil. This will help reduce watering needs, hold down weeds, and also help feed the soil on an ongoing basis as it breaks down.
Some perennials for a sandy soil and sunny location would include: yarrow (Achillea), columbine (Aquilegia), sea thrift (Armeria), Baptisia, Coreopsis, Dianthus, Lychnis, Nepeta, Rudbeckia, Veronica, and Sedum.
For a shady area, with careful soil preparation including ample organic matter, you might try Viola labradorica, Ajuga, Hostas, and Pulmonaria.
Spring blooming bulbs such as crocus and tulips should also do well. Please note that without knowing where in Wisconsin this would be I have named only plants considered winter hardy into USDA winter hardiness zone 3.
Enjoy your new garden!
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