This is an well-established, locally owned nursery and gardening supply retailer. Their specialty is perennials and native plants, although they also carry a good selection of annuals and indoor plants. They don't have trees or large shrubs, but do carry a selection of small shrubs, including hardy roses. The sales areas are well arranged. Perennials have their own room, and annuals are in an adjoining sections. The mind-boggling perennial collection could be overwhelming, but it is well organized. The perennials are laid out alphabetically by name, and also grouped by light and shade preference. There are (usually) helpful labels to tell you the pros and cons, and special needs, of each plant. This really saves time when you are shopping for plants to fill a particular space. I'm an organic garden enthusiast and shop there every year for plants, mulches, and miscellaneous garden supplies. However, if you use conventional gardening methods, they have the normal range of fertilizers and pesticides, and can recommend appropriate products for your situation. They also sell gardening books and yard decor items, but the major emphasis is on plants. I have been completely satisfied with their products and service. Compared to the large chain and big box stores that sell plants and gardening supplies, Johannsen's prices can be somewhat higher. Their value comes from the expertise of the people there, and from the wide selection of native plants that are perfect for rain gardens, prairie planting and other forms of "green" landscaping. The staff are knowledgeable and can either answers your questions, or refer you to another source of information on the rare occasions when they don't know the answer. The location is an unglamorous frontage road on Madison's West Beltline near the intersection with Todd Drive. It can be easy to miss this spot if you are driving by, but it is worth your while to stop there if you are looking for a reliable source of native plants.