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When to plant Sunflower in Jay County County,

Sunflower planted in Jay County County between May 3 and May 24 matures in 100 days — well before the October 16 first frost.

When to Plant Sunflower in Jay County, IN

Jay County, Indiana Zone 6a June

Jay County, Indiana gardeners: here's your June plan

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jay County, Indiana.

Avg. last frost April 26
Avg. first frost October 16
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
To set up a strong July, finish these tasks
  • First harvests: sunflower

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Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Jay County, Indiana is in USDA Zone 6a. The average last spring frost is April 26 and the first fall frost is October 16, giving you a growing season of approximately 173 days.

At an elevation of 1,343 feet, Jay County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Jay County, IN (Zone 6a) Moderate season
173 days
Last Spring Frost April 26
173 growing days
First Fall Frost October 16

Jay County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: Apr 29 🌸 Bloom: Jul 22 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Apr 5 Transplant: May 3 🌸 Bloom: Jul 26 – Oct 18
Safe Start (90%) ✗ May not fit
Start indoors: Apr 21 Transplant: May 19 🌸 Bloom: Aug 11 – Nov 3

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 Jay County

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

Soil pH

Your soil pH (5.8–7.0) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Jay 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
24"
Between Rows

Succession Planting Sunflower

2
successive plantings in your 173-day season

Sow every 8 weeks. Last sowing by Jul 08 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 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 1.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jay 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 ~1,169 GDD — county provides 2,378 GDD Excellent fit

Sunflower Planting Timeline — Jay County, IN

Sunflower Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 3 May 3 – May 17
Direct Sow May 3 May 3 – May 24
Bloom July 26 Jul 26 – Oct 18

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
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

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

173 days in Jay County

Growing Tips for Sunflower in Jay County

Direct sow Sunflower outdoors after April 26 in Jay 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 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Jay County, IN?

Jay County is in Zone 6a with an average last frost of April 26. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jay County, IN?

Jay County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 26 and first fall frost is October 16.

When should I plant Sunflower in Jay County County, ?

In Jay County County, , plant Sunflower after the last frost (around April 26) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Jay County County, for Sunflower?

Jay County County sits in USDA Zone 6a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Jay County County's climate?

Yes — Sunflower grows well in Jay County County's temperate climate. Jay County County averages a 173-day frost-free season, with last frost around April 26 and first frost around October 16.

🌱

Your Jay County Garden Planner — Free

A 22-page printable planner built for Jay 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 Jay County, IN. 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.