Tickseed

Growing & care

• Sun: full sun, minimum 6 hours. Less light reduces flowering and weakens stems.
• Water: low once established. Drought-tolerant by year two; overwatering produces floppy growth and shortens lifespan.
• Soil: lean to average, well-drained. Tolerates sand, rocky soil, and poor ground; rich soil reduces longevity.
• Hardiness: USDA zones 4–9. Often short-lived (3–4 years) in northern zones; longer-lived in southern range.
• Spacing: 12–18 inches.
• Deadhead: removing spent flowers extends the bloom season substantially and prevents excessive self-sowing.

Propagation

Direct-sow seed in fall or early spring; light-sensitive seed should be barely covered with soil. Self-sown seedlings appear readily in undisturbed beds. Division of established clumps in spring or fall works for the species — single crowns split into 3–4 divisions. Modern hybrids and named cultivars are often propagated by tissue culture or cuttings.

Common problems

Foliage decline by midsummer in heat and humidity is common in southern zones — cut the plant back by half to stimulate fresh growth and a second bloom flush. Powdery mildew appears in crowded plantings or wet seasons. Crown rot follows poor drainage. Aphids occasionally cluster on flower buds; a hose spray removes them. Coreopsis is non-toxic to dogs and cats per ASPCA listings.