Coreopsis is our June Plant of the Month for 2024. This genus of plants contains 80 some species and dozens of hybrids across North, South, and Central America. The genus Coreopsis is also its common name., although tickseed is another common name for the plant. Over the last few decades, coreopsis has become one of the most widely hybridized and cultivated perennials from the American landscape. There are hundreds of cultivars.
Among the various species of coreopsis found in North America, there are 6 species native to the Central Great Plains region, though about a dozen or so will grow as perennials or annuals in our area. Of these, Threadleaf (C. verticillata), Plains (C. palmata), and Star tickseed (C. pubescens) are the most hardy and reliable as perennials. But more on those later.
Because of breeding programs like Proven Winners, First Editions, and Garden Debut. we now have to many choices for the garden. It can be difficult to separate out all the different colors and multi-colors for perennials that perform in the landscape. The Mt. Cuba Center in Delaware does an excellent job of trialing plants, but their recommendations are for the Mid-Atlantic region, not the Central Great Plains.
Where to Plant
Coreopsis is native across the United States, in every state except Alaska and Nevada. Most of them are found from the Rocky Mountains eastward. And indeed, across the Great Plains and into the Midwest, that is where the majority of species reside. It can be pretty difficult to identify them without help.
In the garden, depending on cultivar, you can plant them in full sun to part shade. Most of the cultivars of threadleaf and lanceleaf are short, staying between 10 and 24 inches tall and wide. They fit well into a variety of garden types, including cottage, foundation, prairie, meadow, formal, Mediterranean, rain, and more. Do not be afraid to try some different ones in your garden. And there are taller types for more wild areas of the garden.
Species and Cultivars of Coreopsis
With more than 80 species to choose from, how do you decide which to plant? Well, some are native to Central and South America, and will only grow as annuals in our climate. So I choose to focus on the perennial coreopsis species which are the stars of the show. However, even some of these are not long-lived. For example, I had a great threadleaf cultivar, ‘Creme Brulee’ in my Sunny Cottage Garden, which died out after 5 years. However, ‘Zagreb’ can last for a decade or more. But none of them are what I would call long lived.
Threadleaf Coreopsis – C. verticillata
This is the most common species for the landscape. The plants are short and tight growing, spreading by rhizomes. They are not aggressive however, and are fairly easy to remove if they become an issue. Threadleaf grows 1 to 2 feet tall and wide.
- PW Designer Threads Series – includes 4 cultivars; Scarlet Ribbons, Creamy Calico, Golden Needles, and Heartstrings.
- Moonbeam is an older cultivar which has pale yellow flowers.
- Zagreb has an upright, spreading habit, growing 14 inches tall with golden yellow flowers.
- Hot Paprika has dark red flowers.
- Creme Brulee has pale large, pale-yellow flowers.
- Crazy Cayenne has bright red flowers.
Tall Coreopsis – C. tripteris
This species can grow 5 to 9 feet tall. It is found primarily east of the Missouri River, though there are some isolated populations in Eastern Kansas. As a perennial, it is best suited for back of the border or the center of an island. A cultivar call ‘Flower Tower’ is a show stopper in July and August. ‘Gold Standard’ is another cultivar which is an excellent addition to large landscapes, but which may not be suited for smaller yards and gardens.
Plains Coreopsis – C. palmata
One of the more aggressively spreading species, plains coreopsis spreads by rhizomes at a rate of about 1 to 2 feet per year. It blooms in June and July, with large, bright yellow flowers. It is a reliable bloomer, even in hot, dry sites, and is great for native plant gardens or pollinator plots.
Hybrids
Most of the cultivars and series fall under hybrids, having been bred with the use of multiple species. Species like lanceolata, grandiflora, pubescens, rosea, and others were used to create a myriad of colors and color combinations. By combining species like this, you can increase disease resistance and longevity of the plant while gaining new colors.
- Lil’ Bang Series – Daybreak, Red Elf, Starlight
- Uptick Series – Red, Cream & Red, Red & Yellow, Gold & Bronze
- Superstar, Enchanted Eve,
Insect Associations
While coreopsis is not as popular with pollinators as coneflower or blazingstar, it is visited by some butterflies and many types of bees and flower flies. At least 3 moths, the Dimorphic Gray, Wavy-lined Emerald, and Common tan wave all use it as a host plant. And there may be others. On cultivars with multi-colors of red and yellow, the pattern of color guides bees in like a landing zone for a helicopter.
Companion Plants
Because coreopsis fits into many types and styles of gardens, there are a lot of plants which are good companions. In general, native and nonnative grasses, perennials, and annuals are the best partners for them. But I would also recommend the following plants to go alongside them.
- Echinacea
- Goldenrod ‘Fireworks’
- Liatris spicata
- Rudbeckia ‘American Gold Rush’
- Showy sedum
- Bearded & Siberian iris
- Daylilies
- Lavender
- Betony ‘Hummelo’
- Lamb’s Ears
- Dianthus
Conclusion
Coreopsis is a wonderful addition to any full sun garden. There are even cultivars like Zagreb and Moonbeam which are tidy and fit neatly into a foundation planting. I recommend trying several cultivars and species in your garden until you find the ones that fit the best.
Happy planting!
