It’s no wonder the National Garden Bureau named 2018 the Year of the Coreopsis. Coreopsis, commonly called tickseed, are about as carefree as perennials can be. There are types as small as 6 inches and others as tall as 6 feet. Most bloom in summer with lots of cheerful daisy-like flowers. Coreopsis are attractive to birds, bees and butterflies, but not favored by deer.
Some species are annuals, but many are perennials hardy to zone 4. Flowers are most often golden or sunny yellow but may also be colored red, burgundy, salmon, rose, pink or white. They may be solid or bi-colored.
Coreopsis bloom best when planted in full sun but can adapt to part shade. Taller varieties may need staking in part shade, however, as their stems may be lax.
Coreopsis are available as plants at garden centers or their seeds can be sown directly in the garden in spring. Starting them from seed is as easy as preparing an area with well-drained soil, scattering and then pressing seeds into moist soil, covering them very lightly with perlite or vermiculite, and keeping them moist until they germinate. Impatient gardeners can get a head start by starting seeds indoors 4 to 6 weeks before the last expected frost date.
Whether coreopsis start from seeds or plants in your garden, they need regular watering their first year in the garden while their roots establish. In following years, watering during periods of drought is all most species will require.
To keep plants looking their best and to prolong blooming as long as possible, deadhead spent flowers. Some varieties have so many small flowers, it would be nearly impossible to deadhead them one by one. Instead, shear the plants back by a third after their first flush of flowers and they will rebloom in a few weeks.
Here are just a few of the many species of coreopsis for you to try in the garden or in containers.
Coreopsis auriculata, commonly called mouse ear coreopsis or early tickseed, is loaded with brilliant golden-yellow flowers in May and June and continues to bloom intermittently until frost if they are deadheaded. These 6- to 9-inch plants spread slowly without being invasive. Plant them at the front of a border.
Coreopsis grandiflora grows a bit taller – up to 24 inches – and blooms later than C. auriculata. Commonly referred to as large-flowered tickseed, it boasts showy, 2- to 3-inch, deep yellow flowers from early to late summer. Coreopsis grandiflora requires full sun and very good drainage.
It spreads by self-seeding and by rhizomes. If plants begin to look unruly, they can be cut back by half in summer and fresh growth will quickly follow. C. grandiflora is a hardy, but short-lived, perennial. Leave some of its seedlings to ensure it remains in the garden. Plan to divide plants every few years to keep them vigorous. Plant large-flowered tickseed near the front of a perennial border or in meadows or prairie plantings where it can self-seed to its heart content.
C. grandiflora ‘Early Sunrise’ is a small cultivar, growing just 18 inches tall. It was named an AAS Winner in 1989.
Coreopsis integrifolia, or fringeleaf tickseed, blooms later than many other species. It waits to show off its yellow, daisy-like flowers on 30-inch stems until September. Plants grow 18 to 24 inches tall and wide.
It is also different from other types because it thrives in moist soils. If given the growing conditions it prefers, it will form thick colonies. This coreopsis is more difficult to find, but worth the search if you have a sunny spot along a stream, a moist meadow or a perennial border in a low area of your landscape.
C. integrifolia ‘Last Dance’ begins blooming in October, bringing the gardening season to an end with a blooming bang.
Just when you are thinking that all types and varieties of coreopsis must have yellow flowers, Coreopsis rosea comes to the monochromatic rescue. Sometimes called pink coreopsis, it sports yellow-centered, pink-petaled flowers over light green, fine-textured foliage all summer if spent blooms are deadhead. Or cut the entire plant back by half in late summer for another burst of blooms in fall.
Coreopsis rosea, unlike most other types of coreopsis, has little tolerance for drought. Plan to water in dry conditions. In the moist, well-drained, compost-amended soil it prefers, pink coreopsis can become aggressive, spreading by both rhizomes and self-seeding. Plants grow up to 2 feet tall and wide.
C. rosea ‘Heaven’s Gate’ is a bi-colored cultivar featuring bright pink flowers with cherry red near their centers.
C. rosea ‘Nana’ is a small variety – just 8 inches tall – with mauve-pink flowers
Coreopsis tripteris is the giant of the family. Unsurprisingly commonly called tall tickseed, it reaches up to six feet tall. Bright yellow flowers bloom from mid-summer to fall. Another self-seeder if given favored growing conditions, it can form large colonies. It also spreads by rhizomes. Plant tall tickseed at the back of a perennial border or in a prairie planting.
C. tripteris ‘Flower Tower’ grows even taller – up to 8 feet tall. The flowers are larger than the species but their period of bloom is shorter. C. tripteris ‘Gold Standard’ blooms up to six weeks longer than the species.
Coreopsis verticillata is commonly called threadleaf tickseed because of its fine-textured foliage. It spreads by rhizomes, claiming a little more space in the garden each season. Threadleaf tickseed grows 18 to 24 inches tall and wide and begins blooming in early June and continues well into fall. If plants begin to look messy, cut them back by half and new foliage and flowers will follow.
C. verticillata ‘Moonbeam’ displays lemon yellow flowers. It was named Perennial of the Year in 1992.
C. verticillata ‘Zagreb’ shows off sunny golden-yellow flowers. It won the Award of Garden Merit in 2001.
And then there are all the hybrids of coreopsis.
The Big Bang™ series offers a fantastic selection of plants. C. ‘Mercury Rising’ boasts velvety red flowers with gold centers on plants growing 15 to 18 inches tall and wide. C. ‘Star Cluster’ features golden-centered flowers with sparkling white petals blotched with deep purple near the centers. It grows 24 to 30 inches tall and almost as wide.
The UpTick ™ series includes bi-colored cultivars like ‘Yellow & Red’, ‘Gold & Bronze’, and ‘Cream & Red’.
Coreopsis ‘Jethro Tull’ flaunts unique fluted, golden yellow petals on large blooms in June and July. Plants grow 18 inches tall and wide.
Coreopsis ‘Cosmic Eye’ shows off sunny yellow and burgundy red flowers with gold centers. It grows 12 to 15 inches tall and wide.
Coreopsis ‘Crazy Cayenne’ brightens the landscape with reddish-orange centered, sunset orange blooms. It grows 15 to 18 inches tall and wide.
Coreopsis ‘Sienna Sunset’ has flowers that begin blooming burnt sienna but lighten to orange and then to peach.
With all these species, cultivars and hybrids of coreopsis, it is not surprising they have become mainstays in perennial gardens and no wonder the National Garden Bureau decided to name 2018 the Year of the Coreopsis. Let’s all go a little coreopsis crazy this summer.
Garden with me!