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When to Plant Sunflower in Wyandot County, OH

Wyandot County, Ohio Zone 6a May

May in Wyandot County, Ohio — your action list

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

Avg. last frost April 25
Avg. first frost October 22
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Plant out sunflower

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Plant sunflower from seed, right in the garden

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

June prep starts now
  • Starting indoors: sunflower

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Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Wyandot County, Ohio is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 22, giving you a growing season of approximately 180 days.

At an elevation of 654 feet, Wyandot County receives approximately 32.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sunflower during the growing season.

Wyandot County, OH (Zone 6a) Moderate season
180 days
Last Spring Frost April 25
180 growing days
First Fall Frost October 22
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Wyandot County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Feb 22 Transplant: May 3 🍅 Harvest: Jul 12 – Aug 30
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Feb 28 Transplant: May 9 🍅 Harvest: Jul 18 – Sep 5
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Mar 9 Transplant: May 18 🍅 Harvest: Jul 27 – Sep 14

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 Wyandot County

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

Soil pH

Your soil pH (6.0–6.8) is within Sunflower's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Sunflower will thrive.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

2
successive plantings in your 180-day season

Sow every 8 weeks. Last sowing by Jul 14 to harvest before frost.

Plant 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 Sunflower

Sunflower 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 Sunflower Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 3.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.7" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Sunflower 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.

Sunflower needs ~1,232 GDD — county provides 2,610 GDD Excellent fit

Sunflower Planting Timeline — Wyandot County, OH

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 2 May 2 – May 23
Harvest July 18 Jul 18 – Sep 5

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

180 days in Wyandot County

Growing Tips for Sunflower in Wyandot County

Direct sow Sunflower outdoors after April 25 in Wyandot County when soil has warmed and frost danger has passed.

Common pests for Sunflower 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. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Wyandot County, OH?

Wyandot County is in Zone 6a with an average last frost of April 25. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wyandot County, OH?

Wyandot County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 22.

🌱

Your Wyandot County Garden Planner — Free

A 24-page printable planner built for Wyandot 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 Wyandot County, OH. Local conditions may vary. Last updated: May 2026.

Sources & credits

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