Large-flowered tickseed (Coreopsis grandiflora)

Overview

Coreopsis grandiflora, commonly known as Large-flowered tickseed, is a highly valued, low-maintenance perennial celebrated for its profuse display of bright yellow, daisy-like flowers. This species brings vibrant color to the garden from early summer well into the late season, provided spent blooms are managed. Its resilience makes it an excellent choice for gardeners seeking reliable performance with minimal fuss.

Native to prairies and open woodlands across Central and Eastern North America, Large-flowered tickseed naturally colonizes areas with poor or dry substrate. It develops into a tidy clump, typically reaching 1.5 to 2.5 feet tall, blooming profusely atop erect stems. Gardeners appreciate this Coreopsis for its drought tolerance and ability to thrive where other plants might struggle.

The common name ‘tickseed’ refers to the seed’s resemblance to a tick, while the specific epithet grandiflora highlights its large, showy flowers. Planting Coreopsis grandiflora is a simple way to add continuous, cheerful yellow interest while supporting a robust, established perennial in demanding garden situations.

Fast Facts

• Plant Family: Asteraceae
• Plant Type: Herbaceous perennial
• Native Range: Central and eastern North America
• Hardiness Zones: USDA Zones 4-9
• Size at Maturity:
  • Height: 1.5-2.5 ft
  • Spread: 1-1.5 ft
• Bloom Time: June to August
• Bloom Description: Yellow rays and darker yellow center
• Sun Exposure: Full sun
• Water Needs: Dry to medium
• Maintenance Level: Low

How to Grow

Planting Coreopsis grandiflora is best accomplished in spring or fall in a location receiving full sun exposure. This plant thrives in well-drained soil, demanding dryness over excessive moisture. It displays exceptional tolerance for poor, sandy, or rocky soils, making it an ideal candidate for difficult garden spots where drainage is naturally excellent.

Maintenance for Large-flowered tickseed is generally low once established. Water only when the soil feels dry to the touch; established plants handle drought extremely well. Fertilizing is rarely necessary, as rich soil can sometimes lead to floppier growth. The most critical maintenance task is prompt deadheading of faded flowers, which encourages continuous reblooming throughout the summer.

If the plant’s foliage begins to sprawl or declines in appearance during the heat of summer, you can cut the stems back hard. Although Coreopsis grandiflora freely self-seeds, which helps perpetuate the population, it is considered somewhat short-lived. To maintain size and vigor in formal borders, plan to divide clumps every two to three years, typically in the spring.

Landscape Uses

The hardiness and bright color profile of Large-flowered tickseed make it incredibly versatile. It shines when used in traditional cottage gardens or naturalized areas where its tendency to self-seed can be embraced. For borders, Coreopsis grandiflora creates a lively, mid-height splash of yellow that pairs beautifully with blues and purples.

Because it prefers poor, dry soils, seek companions that share these tough requirements. Consider pairing it with Sedums, Russian Sage (Perovskia), or various ornamental grasses. Its drought tolerance makes it perfect for xeriscaping or rock gardens where supplemental water is restricted.

Utilize this plant to soften edges or fill large meadow areas. While it spreads by rhizomes and seed, its clump-forming habit generally keeps it manageable without being overly aggressive, especially when deadheaded routinely.

Standout Features

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. It features daisy-like single flowers, 2-3 inches in diameter, with deep yellow rays notched at the tips surrounding a darker golden center disk. The genus name references the seed’s resemblance to a tick, fitting its common name, tickseed.

Tolerances

• Rabbit
• Deer
• Drought
• Dry Soil
• Shallow-Rocky Soil

Potential Problems

The foliage of Coreopsis grandiflora can sometimes be susceptible to common fungal issues such as powdery mildew, leaf spot, and rust. To minimize these risks, ensure excellent air circulation around the plants and avoid overhead watering late in the day. Choosing compact varieties can help reduce sprawling, which often exacerbates mildew. Furthermore, avoid planting Large-flowered tickseed in heavy, moist, poorly drained soils, as this significantly increases the risk of crown rot.

Frequently Asked Questions

What hardiness zones is Large-flowered tickseed suitable for?

Coreopsis grandiflora is reliably hardy in USDA Zones 4 through 9.

How large does Large-flowered tickseed grow?

This perennial typically reaches a height between 1.5 and 2.5 feet, with a spread ranging from 1 to 1.5 feet wide.

What sun exposure does Coreopsis grandiflora need?

This plant requires full sun to produce its best flowering display.

When does Coreopsis grandiflora bloom?

Large-flowered tickseed generally blooms beginning in June and continues through August, featuring bright yellow rays and a darker yellow center.

Conclusion

The Coreopsis grandiflora is a garden superstar, delivering exceptional summer color with remarkably low demands in terms of soil fertility and water. Ensure you plant this Large-flowered tickseed in a sunny, well-drained location appropriate for USDA Zones 4-9 to enjoy its low-maintenance beauty year after year.

Companion Planting

When designing a sunny, dry border, look for companions that appreciate conditions similar to Large-flowered tickseed. Plants that thrive in full sun and tolerate dryness, such as various varieties of Gaura, Yarrow (Achillea), or Coneflowers (Echinacea), make excellent neighbors. These companions share the aesthetic of open, sunny meadows, allowing the bright yellow of the Coreopsis grandiflora to pop against softer pastels or contrasting blues.

Propagation Tips

While Coreopsis grandiflora readily perpetuates itself via seed—a process you can encourage by skipping deadheading entirely—division is the preferred method for maintaining specific cultivars or rejuvenating older clumps. Dig up the entire plant in early spring before new growth starts, or in the fall after the foliage has died back. Gently tease apart the root ball, ensuring each new section has a healthy set of roots and some viable shoots. Replant immediately at the same depth as the original.