Perennial flowers are favorites of so many gardeners and landscape designers for good reason. Unlike annuals like impatiens and geraniums, perennials come back year after year to bring their lovely colors to the garden. Better yet, many of them grow from single plants into clumps, and reward you with ever more bloom. The downside of perennials is that most of them bloom for just two or three weeks, and then are green mounds of leaves the rest of the growing season. To have color in the garden all season, the classic solution is to plant flowers that bloom at different times and carefully plan a succession of color from spring to fall. As some plants finish blooming, others are beginning. That takes a lot of planning, and extensive knowledge of plants and when they bloom. But there’s an easier way to have a colorful flower garden all summer without the bother of planting anew every spring. Some perennials bloom for many weeks and including them in your landscape will give you long term color. If you cut off the old spent flowers, the plants will bloom longer, even all summer (find some tips at the end of this article). Here are some long bloomers for long-lasting color.
If you’re a daisy lover, you will enjoy the cheerful daisy-like yellow blossoms of Coreopsis. The soft yellow flowers of the aptly named Coreopsis Moonbeam bloom for a month and more in summer. The plants are easy to grow in a sunny spot, and the flowers bloom in abundance on thin stems. When there seem to be more of the little brown buttons of spent flowers on the stems, you can stimulate a new round of bloom by shearing back the plants by about a quarter or a third of their height with scissors or hedge clippers. The plants will produce new flower buds in short order. If you like bright golden yellow, grow Coreopsis grandiflora instead. When this one slows down, cutting off the old flower stems at the base will do the trick.
Another excellent candidate for the nonstop perennial garden are daylilies. Not all daylilies, though. As the name implies, each daylily flower blooms for just a single day. But each flowering stem produces several, and they open in succession. When the last flower on the stem has gone, you cut the stem back to its base. For many daylilies, when the last flowering stem is gone, so are the flowers until next year. But some varieties, notably those with “Stella” as part of their name (the original was Stella de Oro) and those that have “Returns” in their name (such as Happy Returns and Rosy Returns) will produce brand new flower stems, with a new crop of blooms, when the old stems are cut back. Just cut them off at the base.
One of the more interesting plants in the perennial pantheon is Sedum. The sedums best known in flower gardens grow as a clump of thick, fleshy stems and leaves and produce their flowers as heads of tiny florets. When they first develop they resemble heads of broccoli. In late summer, these green clusters of flower buds begin to lighten to light green, then very gradually they turn light pink and slowly deepen, over a span of weeks, toward a salmony bronze color (in the variety Autumn Joy) or hot pink (in newer varieties like Neon and Brilliant). These flowers light up the late summer garden and last for many weeks. As fall settles in, the color deepens further, eventually becoming brown. Some gardeners leave the old flower stalks in the garden all winter, for their sculptural interest.
Perhaps the most carefree of all summer flowers are the group of roses collectively called landscape roses. Knock Out roses are the best known. These plants will bloom happily all summer, all by themselves. All you need to do is water them in dry weather, and fertilize occasionally.
Including these long bloomers in your flower garden, or even building a garden around them, will reward you with reliable color year after year, without having to replant your garden every spring.