When to Plant Coreopsis in Hardin County, TN
Your June gardening checklist
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Hardin County, Tennessee.
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Start coreopsis under lights
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Collect coreopsis at their peak
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in July — start thinking about
- First harvests: coreopsis
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.
Hardin County, Tennessee is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 28, giving you a growing season of approximately 211 days.
At an elevation of 3,095 feet, Hardin County receives approximately 53.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Coreopsis during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Coreopsis root diseases.
Hardin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.7
Drainage
Well Drained
Coreopsis Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Hardin County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (5.4–6.7) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Hardin County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Aug 09 to harvest before frost.
Coreopsis Water Budget
Monthly Watering Guide for Coreopsis
Coreopsis needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Coreopsis Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.2" | 0" | ❄️ Dormant |
| Feb | — | 4.2" | 0" | ❄️ Dormant |
| Mar | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 4.3" | 0" | ❄️ Dormant |
| Dec | — | 4.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Oct in Hardin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Coreopsis Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Coreopsis Planting Timeline — Hardin County, TN
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Bloom | June 9 | Jun 9 – Oct 27 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
211 days in Hardin County
Growing Tips for Coreopsis in Hardin County
Direct sow Coreopsis outdoors after March 31 in Hardin County when soil has warmed and frost danger has passed.
Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
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 Hardin County, TN?
Hardin County is in Zone 7b with an average last frost of March 31. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hardin County, TN?
Hardin County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 28.
Your Hardin County Garden Planner — Free
A 22-page printable planner built for Hardin County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.