Perennials are a great way to add color, with low water usage and little maintenance.
Perennials will usually return year after year. However, selecting and planting perennials takes a little thought and preparation. First, unlike annuals, most perennials will bloom brilliantly for 2-3 weeks. (Many will bloom off and on after the first show.) It is important to take your time selecting plants and asking questions, taking into consideration the bloom time (you do not want everything to bloom at the same time), growth habit (both height and width), and light, water, and maintenance requirements.
Second, prepare your flower beds by incorporating generous amounts of organic matter, such as compost, top soil, peat moss, or blends of these. Fertilizing the beds is important in order to get maximum bloom. If the incorporated organic matter usually does not contain sufficient nutrients, supplemental fertilizer such as a time release perennial food may be needed and beneficial bacteria known as Mycorrhizae.
Third, perennials should be planted on 18″ centers so as not to compete with their neighbor for space. This may leave some gaps in your planting for the first year, so plant a few annuals for color in the gaps.
After your perennials are finished blooming, remove the old flower heads (deadheading). This may encourage reflowering later in the growing season as well as keeping the bed tidy. In the fall, mulch the flower bed after a few heavy frosts and be sure to water the bed during warm dry periods over the winter.
Most perennials will be very drought tolerant after a couple of seasons in the ground, they just have to adapt which usually takes a couple of years. One other item to think about is if you have deer and rabbits as they tend to like many of the perennials here in Colorado.