This time of year I am on the lookout for plants that still look good in the garden. Most plants look pretty tired and haggard by the time September rolls around. Adding in some plants that are starting to bloom or still blooming by late summer breathes some life into a tired landscape.
If you’re looking for a real workhorse of a plant for your perennial garden, consider Coreopsis. Many cultivars of this plant flower beginning in spring and continue into the fall. Most cultivars are right around two feet tall, making them a good medium sized plant in the perennial garden.
A big factor that contributes to Coreopsis’ work horse reputation is that many of the cultivated species are native to North America, so they are well adapted to our climate.
Coreopsis, also commonly called tickseed or calliopsis, is a genus from the family Asteraceae, the plant family that includes familiar members like daisies and black-eyed Susans. The family resemblance is apparent looking at Coreopsis — each flower is daisy-like, usually less than two inches in diameter, typically with petals that have a toothed tip.
Most Coreopsis flowers are yellow. However, there are more and more cultivars being introduced that broaden the color palette into reds oranges, pinks and white. A few cultivars to consider:
Red flowered: ‘Snowberry’ — white flower with burgundy center; ‘Limerock Ruby’ — treat as an annual in Central Illinois, as it is only hardy to Zone 7
Orange flowered: ‘Jethro Tull’ -- yellow-orange flowers, tubular fluted petals ; ‘Early Sunrise’ -- double orange flowers; ‘Nana’ -- early blooming; ‘Sienna Sunset’ -- salmon colored flowers
Pink flowered: ‘American Dream’ -- pink flowers with yellow centers; ‘Sweet Dream’ -- soft pink flowers with purple-red center
White flowered: ‘Alba’ -- tiny white flowers; ‘Pinwheel’ light yellow-white flowers with petals flared like a pinwheel
Foliage is another variable to consider among different species and cultivars of Coreopsis. Leaves may be deeply cut or even fern-like and thready. One fern-leaved cultivar I have in my garden is ‘Zagreb,’ a yellow-flowered cultivar. Its thready foliage is a nice contrast to plants with broader leaves. It flowers most of the summer into fall, and the flowers appear to float among the foliage.
Another cultivar with unique foliage is ‘Tequila Sunrise.’ This Coreopsis has deeply cut foliage with cream colored variegation and bright yellow flowers. Even when not in bloom this plant is beautiful. I have noticed, though, that occasionally solid green or revertant sections appear in this plant.
This is not unusual for a variegated plant. The variegated foliage is genetically a mutant, and occasionally Mother Nature mutates a few cells in the growing point back to the “normal” solid green. I keep my plant variegated by removing the solid green sections as they appear.
Coreopsis typically holds its flowers on wiry stems well above the foliage. To keep Coreopsis flowering consistently, deadheading is a must. The wiry stems make deadheading fairly easy, but the typical mix of spent and new flowers makes this job tedious.
It is far easier to shear off all the flower stems to deadhead in one fell swoop rather than pick through each flower stem. Sources say to shear the plant back as blooming wanes to encourage a new wave of blooms. It took me awhile to build up the courage to shear the entire plant back, but I have done it, and it worked beautifully at stimulating more blooming.
In recent years, I have not had much time for deadheading all the Coreopsis in our garden. One morning, I noticed that the local goldfinch population was happily feeding on the Coreopsis seed heads, the wiry stems easily supporting the small birds. So I guess my lack of time ultimately made the local goldfinches pretty happy.
I have continued to leave at least some of the Coreopsis seed heads for the goldfinches. The plants are not flowering as profusely as they would when regularly deadheaded, but they are still blooming. And now there are more goldfinches to watch in my garden, which is a great tradeoff in my mind.
Besides their extended flowering, Coreopsis are also very drought tolerant and considered deer resistant. These hard working plants deserve a spot in your perennial garden.