Large Flower Coreopsis
Planting Instructions
Here's a detailed planting guide for Coreopsis grandiflora (Large-flowered Tickseed) for direct sowing outdoors in fall or spring, and starting seeds indoors for transplanting, tailored for planting in the USA:
🌿 Coreopsis grandiflora Planting Instructions
Common Name: Large-flowered Tickseed
Plant Type: Perennial (short-lived, often reseeds itself)
Native Range: Southeastern and south-central United States
Pollinator Value: Excellent – attracts bees, butterflies, and other beneficial insects
☀️ Site Selection & Sunlight Requirements
Sunlight: Full sun (6–8+ hours/day) is ideal.
Tolerates light shade but best flowering occurs in full sun.
Soil: Adaptable to a range of soils including sandy, loamy, and rocky.
Drainage: Must be well-drained – avoid heavy, wet soils.
pH Range: Neutral to slightly alkaline preferred, but tolerant of most soil pH levels.
🌱 Soil Preparation
Loosen top 6–8 inches of soil before sowing.
Remove all weeds and debris.
Amend soil with light compost if it's very poor, but avoid rich soil – this can reduce flowering and promote floppy growth.
Avoid heavy fertilizers, as this can produce excess foliage with fewer flowers.
🌾 Direct Sowing Outdoors – Fall or Spring
Fall Sowing
When: After first frost but before the ground freezes (late fall).
Why: Allows natural cold stratification, improving spring germination.
How:
Broadcast seeds on soil surface.
Lightly press seeds into soil; do not bury deeply.
Cover lightly with 1/16 to 1/8 inch of soil or fine mulch.
Water lightly if dry. Natural moisture over winter will aid germination.
Spring Sowing
When: After last frost when soil is workable.
Stratification: Optional — 1–4 weeks of cold stratification can improve germination but is not strictly required.
How:
Prepare soil and sow seeds on surface or very lightly cover (1/16 to 1/8 inch).
Water consistently until germination, keeping soil moist but not waterlogged.
Germination typically occurs in 10–20 days.
🌱 Starting Seeds Indoors for Spring Transplanting
When to start indoors: 6–8 weeks before last frost date
Stratification: Not required but optional cold moist stratification for 1–4 weeks may enhance germination rates.
Scarification: Not needed
Sowing indoors:
Sow on top of moist seed-starting mix or barely press in.
Light is helpful for germination — do not cover deeply.
Maintain temperature at 65–75°F.
Use humidity dome or plastic cover until germination (10–20 days).
Transplanting outdoors: Harden off seedlings for a week, then transplant after frost risk is past.
💧 Watering
Keep soil evenly moist during germination and early growth.
Once established, very drought tolerant — water only during prolonged dry periods.
Avoid overwatering — this can cause root rot or weak stems.
✂️ Maintenance Tips
Deadheading spent flowers promotes continuous bloom.
Cut back in fall or early spring to rejuvenate plant growth.
May require staking in richer soils or windy locations.
Plants may be short-lived but often self-seed under favorable conditions.
Divide clumps every 2–3 years if needed to maintain vigor.
❌ Is it Invasive?
Not invasive.
Can self-sow modestly, but is easy to control by removing unwanted seedlings.
A well-behaved addition to native gardens, pollinator gardens, and prairie plantings.
🌼 Other Notes
Excellent companion for other drought-tolerant wildflowers like:
Ratibida columnifera
Gaillardia pulchella
Monarda citriodora
Great choice for xeriscaping, meadow gardens, or low-maintenance borders.
Provides long-season blooms from early summer to frost with proper care.
