whorled tickseed Interesting Notes

"Threadleaf coreopsis (also commonly called whorled coreopsis) is a rhizomatous perennial which typically grows in dense, bushy clumps to 1-3' tall. 'Zagreb' is more compact (to 1.5' tall) and features bright yellow, daisy-like flowers (1-2" diameter) with untoothed rays and darker yellow center disks. Flowers appear singly in loose clusters (cymes) in a lengthy late spring to late summer bloom period which sometimes extends to first frost. Shearing plants in mid-summer (early August) when bloom usually tapers down will encourage a fall rebloom. Palmately 3-parted leaves with thread-like segments lend a fine-textured and airy appearance to the plant. Plants in the genus Coreopsis are sometimes commonly called tickseed in reference to the resemblance of the seeds to ticks."- Missouri Botanical Garden

Not very often do you find a straight species that holds its own against well-loved cultivars and selections but Coreopsis verticillata is one of those cases. Growing 2’-3’ high, it is loosely covered with bright lemon yellow flowers and fine green lacy foliage. Stems and flowers are at varying heights and the billowy blooms move and feel light due to their staggered nature. This plant is drought-tolerant and wonderful in informal sunny gardens and along the edge of walkways and roadsides.

Coming from wood edges, pine savannas, and oak savannas, Coreopsis verticillata is native to Maryland to South Carolina to Kentucky and Tennessee. It prefers sun to lightly shaded sites in sandy, well-drained soil. It does well in garden soil but the water-holding capacity of heavy clay soils can lead to crown rot.

Coreopsis species support over 40 different species of insects including some predatory insects which are essential for a garden strong ecosystem.

Coreopsis verticillata 'Zagreb' Growing and Maintenance Tips

Easily grown in dry to medium moisture, well-drained soils in full sun. Thrives in poor, sandy or rocky soils with good drainage, but grows easily in any average, well-drained soils. Tolerant of heat, humidity and drought. Deadheading of spent flower stalks will encourage additional bloom - shear in mid to late summer to promote a fall rebloom and to remove any sprawling or unkempt foliage. 'Zagreb' can spread in the garden by rhizomes and self-seeding, particularly in moist, fertile soils. Propagate by division in spring or fall. 

Good Substitutions

Coreopsis 'Crème Brûlée'

Coreopsis 'Sienna Sunset'

Coreopsis pubescens 'Sunshine Superman'

Coreopsis Permathread™ 'Red Satin'