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When to Plant Zinnia in Coshocton County, OH

Coshocton County, Ohio Zone 6b July

Your July gardening checklist

A quick July briefing for Coshocton County, Ohio gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 29
Avg. first frost October 12
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Start harvesting zinnia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of August
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Coshocton County, Ohio is in USDA Zone 6b. The average last spring frost is April 29 and the first fall frost is October 12, giving you a growing season of approximately 166 days.

At an elevation of 757 feet, Coshocton County receives approximately 30.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Zinnia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Coshocton County, OH (Zone 6b) Moderate season
166 days
Last Spring Frost April 29
166 growing days
First Fall Frost October 12

Coshocton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: Apr 27 🌸 Bloom: Jul 6 – Oct 12
Recommended (50%) ✗ May not fit
Start indoors: Apr 1 Transplant: Apr 29 🌸 Bloom: Jul 8 – Oct 14
Safe Start (90%) ✗ May not fit
Start indoors: Apr 19 Transplant: May 17 🌸 Bloom: Jul 26 – Nov 1

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 Coshocton County

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

Soil pH

Your soil pH (6.1–7.0) is within Zinnia's preferred range (5.5–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Zinnia.

Organic Matter

Organic matter is excellent (4.0%) — Zinnia will thrive.

How to Plant Zinnia

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

Succession Planting Zinnia

3
successive plantings in your 166-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Zinnia Water Budget

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

Monthly Watering Guide for Zinnia

Zinnia 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 Zinnia Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.2" 2.5" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.3" 0" ✅ Rainfall sufficient
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.5" 0" ✅ Rainfall sufficient
Oct 2.2" 2.2" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Zinnia 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.

Zinnia needs ~991 GDD — county provides 2,531 GDD Excellent fit

Zinnia Planting Timeline — Coshocton County, OH

Zinnia Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 29 Apr 29 – May 20
Bloom July 8 Jul 8 – Oct 14

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

Month-by-Month Timeline

MonthActivities
January
February
March
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

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

166 days in Coshocton County

Growing Tips for Zinnia in Coshocton County

Direct sow Zinnia outdoors after April 29 in Coshocton County when soil has warmed and frost danger has passed.

Common pests for Zinnia 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 when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Coshocton County, OH?

Coshocton County is in Zone 6b with an average last frost of April 29. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coshocton County, OH?

Coshocton County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 29 and first fall frost is October 12.

🌱

Your Coshocton County Garden Planner — Free

A 22-page printable planner built for Coshocton 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 Coshocton County, OH. Local conditions may vary. Last updated: July 2026.

Sources & credits

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