You might find some true perennials in an “annuals,” department, either because (a) they are perennials in warmer places but still have value here even for a one-season show, or (b) they are truly hardy perennials here, but they mix very well with annuals in containers. (In that case, enjoy them in the container but plant them in the soil in late summer and they may come back.)
3. Gardeners choose perennials for more than the flowers. This is the key to perennial gardening: We choose the plants for more than the flowering period, which is often only two or three weeks. We value their foliage, fragrance, ecological/pollinator value or their forms. Learn about the seasonlong features of a perennial that you see flowering, to decide if it has merit as a longtime resident in your garden.
A gardener’s highest achievement may be the orchestration of a perennial border, in which the sequence of bloom, complementary plant placement and balance of textures and forms are planned.
In my decades of viewing gardens, my best memory is a peak moment when I first visited the RHS (Royal Horticultural Society) Wisley Garden in Surrey, England. I stood at the beginning of the world-famous 420-foot-long double perennials border and felt overwhelmed. Tears in my eyes. I thought, “This is the epitome of the art of gardening.”