There are a few nurseries in the Twin Cities and surrounding area that propagate some of the native wild flowers, along with their cultivated perennials, and sell them as potted plants in the spring. Of course potted plants will be more expensive than the bare-rooted ones that can be obtained in the fall from various nurseries. To expand the garden, some vegetative propagation can be done in early May. Don't disturb those in flower or about to flower, but others can be divided. The basal rosettes of the cardinal flower can be separated and similarly, the offsets of the large-flowered penstemon can be cut apart.
Native ferns add interest in the wild flower garden.
One of the most satisfactory is the maiden-hair fern . Because they need long cold periods prior to germination, many wild flower seeds germinate better when planted in the fall or very early plants that are new to you. Find out their spring. With older seed scratch the coat lightly and soak the seed in water for a few hours before planting. They will germinate quickly.