An Alternative Groundcover: Coreopsis
Many people ask how to keep weeds down in their planting beds, or how to fill empty space in their beds, or even what to plant as an alternative to ivy, juniper, or other commonly used groundcovers. One answer: consider using one of the many species of coreopsis as an alternative groundcover, as it offers numerous benefits, especially those species native to the mid-Atlantic region.
Coreopsis is one of my all-time favorite perennials and I use it quite a lot in my designs for groundcover. It fills space with a low-flowering species and brightens a corner of a garden with the intense yellow blooms. (Coreopsis comes in varying shades of yellow and may even have oranges, reds, and pinks in their color spectrum.)
Their name comes from the Greek words “koris” and “opsis” meaning “like a bug.” Their common name is tickseed, which also reflects this bug-like meaning. The name comes from the seeds’ resemblance to ticks.
Birds may feed on coreopsis seeds, but oftentimes homeowners cut back their blooms before—or right after—they go to seed. Consider deadheading once during mid-season and then let the second flush go to seed in the fall, providing some much-needed nourishment to our feathered friends.
Growing coreopsis is quite easy and can be done in the garden or in containers on a patio. They prefer well-drained soils and will do very well in sandy areas. Some species form clumps and some spread by rhizomes (underground stems). Coreopsis verticillate, or thread leaf coreopsis, spreads by these underground stems and overwinters better than species that clump. They prefer full sun and bloom best under these conditions.
There are numerous cultivars and varieties of Coreopsis verticillata. “Moonbeam” is very common and has a beautiful creamy yellow flower. They are readily available at local nurseries. Mt. Cuba, in northern Delaware, performed trials featuring coreopsis that concluded with a report in 2015. They found one of the best-performing thread leaf coreopsis was “Zagreb,” which only grows to be roughly 20 inches in height. It also grows in such a way that all their blooms are close to the same height, making it appear like a carpet of gold in your garden. Because they spread by rhizomes, be sure to give them room as they can expand up to two feet over a couple of years.
Besides being attractive, coreopsis also helps to control weeds since they can grow to be a dense groundcover, suppressing weedy plants. They also attract pollinators like bees, butterflies, and other beneficial insects. As mentioned previously, birds consume their seeds if left to remain on the plant after pollination. Coreopsis is drought tolerant and said to be rabbit and deer tolerant as well.
Planting coreopsis in your gardens will most assuredly bring joy and cheer with their boundless blooms of golds and yellows that brighten the garden, as well your day. Coreopsis can also be a sharing plant as they can be divided once every two to three years to help keep their appearance and shape. Many of my previous articles talk of sharing the bounty that’s in the garden with friends and family, and coreopsis works very well for that purpose.
With all these amazing attributes and benefits, it sounds like coreopsis is a must-have plant in your landscape! Try it—you won’t be disappointed.
Be well, and let’s garden together. ▼
Eric W. Wahl is Landscape Architect at Pennoni Associates, and President of the Delaware Native Plant Society.