When to Plant Coreopsis in Chester County, PA
Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.
Chester County, Pennsylvania is in USDA Zone 7a. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.
At an elevation of 761 feet, Chester County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Coreopsis during the growing season.
Chester County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Coreopsis Planting Timeline — Chester County, PA
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 16 | Apr 16 – May 7 |
| Bloom | June 25 | Jun 25 – Nov 5 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
194 days in Chester County
Growing Tips for Chester County
Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Coreopsis in Other Locations
Frequently Asked Questions
When should I plant Coreopsis in Chester County, PA?
Chester County is in Zone 7a with an average last frost of April 16. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Chester County, PA?
Chester County, Pennsylvania is in USDA Hardiness Zone 7a. The average last spring frost is April 16 and first fall frost is October 27.
Your Chester County Garden Planner — Free
A 22-page printable planner built for Chester County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.