CORVALLIS, Ore. - To keep a colorful and low maintenance flower garden through the summer and fall, it is best and easiest to grow water-efficient summer and fall-blooming perennials. The time to plant these is in the spring, so they have time to get established before their blooming season.
Oregon State University Extension Service horticulturists recommend the following summer and fall blooming perennial flowers for mostly sunny areas. These need a minimum of watering, once they are established:
- Yarrow (Achillea): These hardy fragrant plants have finely divided fern-like leaves with flat topped clusters of white, pink, red or yellow flowers. There are low growing and taller varieties. Excellent for drying.
- Coreopsis: A relative of the sunflower, with bright yellow flowers. These 2 to 3 foot high plants will give a show of color throughout the summer.
- Purple Coneflower (Echinacea): Big purple daisy-like flowers with purple centers and drooping purple flowers, also native to the prairies. Clumps of coneflowers grow from 4 to 5 feet high and lower from late summer into early autumn.
- Columbine (Aquilegia): These spring or early summer-blooming perennials are easily grown from seeds or starts and will self sow. Oregon’s native species, Aquilegia formosa is a good nectar source for hummingbirds, bees and butterflies. All columbine prefer cool sites with part shade, and thrive in rich, organic soil, but will also grow in full sun.
- Globe thistle (Echinops): With steel blue globe-shaped flowers, this gray-green prickly perennial blooms from mid-summer into fall. It makes excellent cut flowers.
- Blanket Flower (Gaillardia): Also a member of the sunflower family, with gray-green foliage and brilliant yellow flowers, banded with red, maroon or orange. Easy to sow from seed, they often self-sow. Blooms summer into fall.
- Flax (Linum): These sky-blue cup shaped flowers only last a day, but will keep blooming for a month or more. Wispy, narrow leafed stems grow to two feet in clumps. Easy to grow from seed. Blooms late spring to summer.
- Penstemon: Native to dry rocky areas in the high mountain meadows of the west, the many types of penstemons have showy tubular blossoms in red, purples to blues. Species range from sprawling mats to uprights to shrubs.
- Evening primrose (Oenothera): Native to desert regions, these plants produce fragrant white, yellow or pink evening-blooming flowers which die back after blooming. They need little care.
For shadier areas, try these drought tolerant perennials:
- Lily of the Nile (Agapanthus): Clumps of broad, strap-shaped leaves send up lovely blue or white round clusters of flowers. Loves to be watered, but can tolerate drought. It has heavy roots for water storage.
- Corydalis lutea: this delicate looking, yellow flowered perennial is a close relative of bleeding heart. As "tough as nails." Can take moist or dry soil, sun or shade. Reseeds itself readily. Blooms from May until the first hard frost.
- Mexican daisy (Erigeron): Sprawling or trailing evergreen with white, red or pink daisy-like flowers. Blooms continuously for months. Self sows and tolerates sun or shade. Very drought tolerant.
- Thyme: Perennial mat formers or shrubby species. Good for ground cover. Has small leaves. Small light-colored flowers bloom in summer. Grows best in sun or light shade. Common thyme is fragrant herb that can also be used as low edge plant.
- Flowering sage (Salvia): Tropical flowering perennials, flowering sages come in all colors of the rainbow. Can be great for pots and hot spots. May not overwinter in our climate unless protected.
Want to learn more about water-wise gardening? Using native plants in your home landscape can be a great start. Linda McMahan has developed a website of the Yamhill County office of the OSU Extension Service that offers plant lists, pictures and great information and links about waterwise plants and gardening in the Pacific Northwest. Go to the OSU Extension Service's Yamhill County native plants Web site.