May 8, 2002
Growers' Six Pack: Coreopsis

By Janet Anderson, J.E.A. Perennials

To become a classic is a noble achievement. With the vast, almost infinitesimal array of herbaceous perennials available to the gardening public, it is still possible to count on one hand (OK, maybe two or three) the standards that are, or should be, included in every landscape. Criteria include hardiness, longevity, adaptability and, of course, a beautiful appearance either in flower or foliage, or better yet, a winner that combines both. When an excellent plant is identified, it is often useful to explore further within the genus to seek out closely related plants, looking for variation in appearance with minimal sacrifice of the attributes to which you were first attracted. One such useful genus is Coreopsis, with the common (and as usual, unattractive) name of Tickseed. Not just another LWD (little white daisy), these plants are often the stars of the summer border. They are perfectly happy in full sun but tolerant of very light shade and are not overly fussy about water or soil conditions. The ubiquitous "moist but well-drained" site is preferable. They are not plants that are able to sit in water but a few are good candidates for drought situations. Once established, however, these plants require minimal irrigation. Coreopsis make excellent companion plants with other classics, such as Sedum 'Autumn Joy' (aka Hylotelephium 'Herbstfreude' - yes, our friends, the taxonomists have been busy again, but that's another story) and ornamental grasses such as Calamagrostis 'Karl Forester' and Heuchera 'Plum Pudding'. There are several varieties of Coreopsis that merit attention...

Coreopsis grandiflora 'Walcoreop'
(better known as Flying Saucers)

A recent introduction from David Tristram who brought us Spirea 'Magic Carpet' and Scabiosa 'Butterfly Blue' (the PPA Perennial Plant of the Year 2000), Coreopsis grandiflora 'Walcoreop' has a fairly compact growth habit (35 cm in height). Very large golden yellow flowers seem to glow from across the garden. Again, bloom time is June through frost, and this plant will also benefit from an enforced rest. USDA zone 5.
Photo courtesy of Eric Olsen, DeVroomen Garden Products.

Coreopsis verticillata 'Zagreb'
Similar to its famous cousin but with distinct features, 'Zagreb's needle-like foliage is a bright green while its flowers are a deep golden yellow. The plants are also notably more compact, growing to a height of only 25 to 30 cm. USDA zone 3.
Photo courtesy of Eric Olsen, DeVroomen Garden Products.

Coreopsis grandiflora 'Early Sunrise'
1989 AAS. Double golden yellow flowers from June to frost. Dark green foliage will form sturdy plants, 50 cm in height. Deadhead flowers for more blooms, but remove all blooms in fall to give the plant a chance to build up reserves for the winter. USDA zone 5.
Photo courtesy of Eric Olsen, DeVroomen Garden Products.

Coreopsis lanceolata 'Sterntaler'
Producing a mass of yellow flowers with a brown central circle from June until frost, 'Sterntaler' reaches about 40 cm in height. Deadheading of spent flowers will encourage fresh blooms. USDA zone 4.
Photo courtesy of Eric Olsen, DeVroomen Garden Products.

New & Noteworthy!

Coreopsis 'Tequila Sunrise'
An exciting new introduction from Ken and Linda Smith of Columbus, Ohio, Coreopsis 'Tequila Sunrise' is thought to be a hybrid between lanceolata and grandiflora. Dark green leaves are variegated with cream and yellow. In cool weather (spring and fall), pinks and reds are also apparent. Large yellow daisies with a red eye appear in late spring to early summer and again in the fall. 'Tequila Sunrise' is a great foliage accent, even without the blooms. Height 40 cm. USDA zone 5.
Photo courtesy of Paul Zammit.

Must-have staple!

Coreopsis verticillata 'Moonbeam'
This is the workhorse of the genus. Probably best known and certainly deserving of its status as a "must have" perennial, 'Moonbeam' features lacy dark green foliage, enhanced by masses of soft yellow daisies, blooming from June to frost. It is a little slow to emerge in spring but exhibits rapid growth as temperatures increase. Reaching a height of 35 to 45 cm, 'Moonbeam' is an excellent choice for mass plantings. Drought tolerant when established. Hardy to USDA zone 3. Chosen as the Perennial Plant Association (PPA) Plant of the Year in 1992.
Photo courtesy of Eric Olsen, DeVroomen Garden Products.