The list of possible perennial plants is long. See fact sheet 7.405, Herbaceous Perennials for a listing of species. Many new, improved varieties are introduced annually that are adapted to our climate.
Choose plants for flower color, bloom period, height and light requirements. Compile a chart, organizing this information in an easily viewed manner. Bloom times may vary with weather, soil conditions and elevation. At higher elevations, bloom times are later. See fact sheet 7.406,Flowers for Mountain Communities, for more information on gardening at higher elevations.
Tall perennials, such as delphinium, foxglove, and hollyhock often require staking in windy sites. Consider dwarf varieties in windy areas or when stakes are undesirable.
The most important consideration in selecting plants for a perennial garden is to group them according to their environmental and cultural requirements. For example, place drought-tolerant plants together at the top of a slope and moisture-loving plants in a swale or low spot where runoff collects. This is called hydrozoning.
Other plant characteristics to consider for easier maintenance include: cold hardiness, heat tolerance, insect and disease resistance, cultural requirements (staking, pruning, fertilizing, deadheading, frequent division), and invasiveness.