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When to Plant Coreopsis in Beloit, OH

Mahoning County, Ohio Zone 6a June

What to do in June

We've pulled the most time-sensitive tasks for Mahoning County, Ohio this June and put them front and centre. Tackle them in order.

Avg. last frost April 30
Avg. first frost October 18
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
Before July arrives, get these ready
  • Starting indoors: coreopsis
  • First harvests: coreopsis

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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.

Beloit, Ohio is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 18, giving you a growing season of approximately 171 days.

At an elevation of 759 feet, Mahoning County receives approximately 37.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Coreopsis during the growing season.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Beloit, OH (Zone 6a) Moderate season
171 days
Last Spring Frost April 30
171 growing days
First Fall Frost October 18

Beloit Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Coreopsis Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 22 Transplant: May 3 🌸 Bloom: Jul 12 – Nov 1
Recommended (50%) ✗ May not fit
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 16 – Nov 5
Safe Start (90%) ✗ May not fit
Start indoors: Mar 20 Transplant: May 29 🌸 Bloom: Aug 7 – Nov 27

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 Beloit

How your county's soil matches Coreopsis's growing requirements.

Soil pH

Your soil pH (6.2–6.8) is within Coreopsis's preferred range (5.5–7.5).

Soil Texture

The silt loam soil in Mahoning County is excellent for Coreopsis — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) — Coreopsis will thrive.

How to Plant Coreopsis

0.1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Coreopsis

3
successive plantings in your 171-day season

Sow every 6.9 weeks. Last sowing by Jul 30 to harvest before frost.

Coreopsis Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 4.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 3.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.7" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Mahoning 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 needs ~1,015 GDD — county provides 2,479 GDD Excellent fit

Coreopsis Planting Timeline — Beloit, OH

Coreopsis Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Bloom July 16 Jul 16 – Nov 5

Plant 0.1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors Direct Sow
June
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

171 days in Mahoning County

Growing Tips for Coreopsis in Beloit

Direct sow Coreopsis outdoors after April 30 in Mahoning 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 →

🌱

Your Mahoning County Garden Planner — Free

A 22-page printable planner built for Mahoning 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Mahoning County, OH. Local conditions may vary. Last updated: June 2026.