When to plant Coreopsis in Bay County County,
In Bay County County, plant Coreopsis in spring between May 17 and June 7, once soil temps hold above 50°F. Bay County County's last frost averages May 10, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 80 days before the first frost on October 7.
When to Plant Coreopsis in Bay County, MI
Your June game plan for Bay County, Michigan
A quick June briefing for Bay County, Michigan gardeners — what's urgent, what's next, and what can wait.
To set up a strong July, finish these tasks
- Starting indoors: coreopsis
- 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.
Bay County, Michigan is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.
At an elevation of 835 feet, Bay County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Coreopsis during the growing season.
Bay County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.8
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 Bay County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (6.1–6.8) is within Coreopsis's preferred range (5.5–7.5).
Soil Texture
The silt loam soil in Bay County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Coreopsis will thrive.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Jul 19 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 3.1" | 0" | ❄️ Dormant |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Bay 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 — Bay County, MI
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 8 | Mar 8 – Mar 22 |
| Transplant Outdoors | May 17 | May 17 – May 31 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Bloom | July 26 | Jul 26 – Nov 15 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Direct Sow |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| 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: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
150 days in Bay County
Growing Tips for Coreopsis in Bay County
Direct sow Coreopsis outdoors after May 10 in Bay 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 Bay County, MI?
Bay County is in Zone 6a with an average last frost of May 10. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bay County, MI?
Bay County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.
When should I plant Coreopsis in Bay County, ?
In Bay County, , plant Coreopsis after the last frost (around May 10) and before the first frost (around October 7). Best results when soil holds above 50°F.
What growing zone is Bay County, for Coreopsis?
Bay County sits in USDA Zone 6a. Coreopsis grows reliably in zones 3a through 9b, so it's a good fit here.
Can Coreopsis grow in Bay County's climate?
Yes — Coreopsis grows well in Bay County's temperate climate. Bay County averages a 150-day frost-free season, with last frost around May 10 and first frost around October 7.
Your Bay County Garden Planner — Free
A 22-page printable planner built for Bay County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.