Perennial of the Month-- August 2007 

(core-ee-OP-siss ver-ti-sill-A-tah) (pronunciation at link, turn up volume if too low)

Common name: Golden Gain tickseed, threadleaf coreopsis

Family: Asteraceae, Aster (composite, daisy)

Height x width: 16-18" x 15-18"

Growth rate, habit: moderate, clumping

Foliage: palmately 3-parted with thread-like segments (hence the common name)

Flowers: golden, larger (2" across) than many cultivars, long period of bloom midsummer (may begin late spring in warm climates); untoothed ray flowers, darker yellow center disks; single appearance in loose clusters (cymes)

Hardiness: USDA zones 4-9

Soil: well-drained, moist, tolerates dry once established; also tolerates sandy to rocky poor soils

Light: full sun

Pests and problems: none significant; crown rot in poorly drained soils; uncommon are botrytis, aster yellows, powdery mildew, fungal leaf spots

Landscape habit, uses: borders edges or massed, along walks, cottage gardens, rock gardens, naturalized areas, attracts butterflies; combines well with 'Firecracker' clumping loosestrife, shasta daisies, daylilies, Helen's flower, blue mist shrub, speedwells, blanket flower, perennial salvia, lavender, Russian stonecrop or Autumn stonecrops

Other interest: a Blooms of Bressingham introduction; common name from resemblance of seeds to ticks; one of best cultivars with long flowering, many flowers, uniform habit and flowering

Other culture: in warmer climates shear first flowers off when done to encourage later rebloom, may self seed or spread by rhizomes in ideal conditions; may sprawl in moist and fertile soils

Propagation: division early fall or early spring (best), cuttings

Sources: specialty perennial nurseries local, mail order, and online; Blooms of Bressingham licensed retailers (www.bobna.com)