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When to Plant Cosmos in Meigs County, OH

Meigs County, Ohio Zone 6b June

Your June planting checklist for Meigs County, Ohio

Each item below is timed to Meigs County, Ohio's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 24
Avg. first frost October 22
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
July will be here before you know it — start on
  • First harvests: cosmos

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Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Meigs County, Ohio is in USDA Zone 6b. The average last spring frost is April 24 and the first fall frost is October 22, giving you a growing season of approximately 181 days.

At an elevation of 843 feet, Meigs County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Meigs County, OH (Zone 6b) Moderate season
181 days
Last Spring Frost April 24
181 growing days
First Fall Frost October 22

Meigs County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🌸 Bloom: Jun 25 – Oct 8
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Mar 27 Transplant: Apr 24 🌸 Bloom: Jul 3 – Oct 16
Safe Start (90%) ✗ May not fit
Start indoors: Apr 18 Transplant: May 16 🌸 Bloom: Jul 25 – Nov 7

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 Meigs County

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

Soil pH

Your soil pH (6.2–7.1) is within Cosmos's preferred range (6.0–8.0).

Soil Texture

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

Drainage

Drainage is adequate for Cosmos.

Organic Matter

Organic matter is excellent (5.2%) — Cosmos will thrive.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

3
successive plantings in your 181-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

Cosmos Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cosmos

Cosmos 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 Cosmos Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.4" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Meigs County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cosmos 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.

Cosmos needs ~1,256 GDD — county provides 3,031 GDD Excellent fit

Cosmos Planting Timeline — Meigs County, OH

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 24 Apr 24 – May 15
Bloom July 3 Jul 3 – Oct 16

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

181 days in Meigs County

Growing Tips for Cosmos in Meigs County

Direct sow Cosmos outdoors after April 24 in Meigs County when soil has warmed and frost danger has passed.

Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Meigs County, OH?

Meigs County is in Zone 6b with an average last frost of April 24. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Meigs County, OH?

Meigs County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 24 and first fall frost is October 22.

🌱

Your Meigs County Garden Planner — Free

A 22-page printable planner built for Meigs County (Zone 6b). 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 Meigs County, OH. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.