Common Name: large-flowered tickseed
Type: Herbaceous perennial
Family: Asteraceae
Zone: 4 to 9
Height: 2.50 to 3.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: June to August
Bloom Description: Yellow
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy, Good Cut
Attracts: Butterflies
Tolerate: Rabbit, Deer, Drought, Dry Soil, Shallow-Rocky Soil
Culture
Easily grown in dry to medium moisture, well-drained soil in full sun. Thrives in poor, sandy or rocky soils with good drainage. Tolerant of heat, humidity and drought. Prompt deadheading of spent flower stalks encourages additional bloom and prevents any unwanted self-seeding. Freely self seeds and can become somewhat weedy. Also spreads by rhizomes. Plants are somewhat short-lived and self-seeding helps perpetuate a good planting in the garden. Plants may be cut back hard in summer if foliage sprawls or becomes unkempt. When grown in borders or other formal garden areas, division may be needed every 2-3 years to maintain robustness. May be grown as annuals.
Best to propagate 'Mayfield Giant' vegetatively.
Noteworthy Characteristics
Coreopsis grandiflora, commonly called large-flowered tickseed, is native to prairies, glades, open woods, thickets, roadsides and open ground in the southeastern U.S. from Florida to Texas and New Mexico north to Georgia, Missouri and Kansas. It typically grows in a clump to 2' tall. Daisy-like single flowers (2-3" diameter) feature deep yellow rays (notched at the tips) surrounding a darker golden yellow center disk. Flowers appear singly atop slender, erect stems rising to 2' tall. Flowers typically bloom from late spring to late summer and sometimes into fall, though bloom period can be much shorter if spent flowers are not regularly deadheaded. Upper leaves are pinnatifid and deeply lobed, but lower leaves at the base of the plant are lobeless and linear. Through introduction and garden escapes, this coreopsis has become established in the eastern and central U.S. well north of its native range.
The genus name comes from the Greek words koris meaning "bug" and opsis meaning "like" in reference to the shape of the seed which resembles a bug or tick.
Specific epithet means large-flowered.
Common name of tickseed is in reference to the resemblance of the seeds to ticks.
'Mayfield Giant' is a cultivar which features large, solitary, yellow, daisy-like flowers (2-3" diameter) with yellow rays (lobed at the tips) and darker yellow center disks atop slender, erect stems rising 24-36" tall. Flowers typically bloom from late spring to late summer and sometimes well into fall, though bloom period can be much shorter if spent flowers are not regularly deadheaded. Spatulate to lanceolate leaves. Lower basal leaves are mostly entire, while smaller stem leaves are often pinnately lobed.
Problems
Foliage is susceptible to powdery mildew, leaf spot and rust. Compact plants are less likely to sprawl than taller varieties of coreopsis. Crown rot may occur if grown in moist, poorly drained soils.
Uses
Borders. Also effective in naturalized areas, meadows, prairies or cottage gardens. Good plant for areas with poor, dry soils.