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When to Plant Sunflower in Haywood County, TN

Haywood County, Tennessee Zone 8a May

This month in Haywood County, Tennessee

Welcome to May in Zone 8a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 1
Avg. first frost October 29
Soil temp (4") 58°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start sunflower indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

June will be here before you know it — start on
  • First harvests: 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.

Haywood County, Tennessee is in USDA Zone 8a. The average last spring frost is April 1 and the first fall frost is October 29, giving you a growing season of approximately 211 days.

At an elevation of 3,782 feet, Haywood County receives approximately 51.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Sunflower during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Haywood County, TN (Zone 8a) Long season
211 days
Last Spring Frost April 1
211 growing days
First Fall Frost October 29

Haywood County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🍅 Harvest: Jun 18 – Aug 6
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Feb 11 Transplant: Apr 15 🍅 Harvest: Jun 24 – Aug 12
Safe Start (90%) ✓ Fits season (83 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jul 10 – Aug 28

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 Haywood County

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

Soil pH

Your soil pH (5.4–7.1) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Sunflower.

How to Plant Sunflower

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

Succession Planting Sunflower

3
successive plantings in your 211-day season

Sow every 8 weeks. Last sowing by Jul 21 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 4.1" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 5.4" 0" ❄️ Dormant
Apr 2.2" 4" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 3.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4.7" 0" ✅ Rainfall sufficient
Sep 2.2" 4.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 4.1" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Haywood 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 ~1,679 GDD — county provides 4,167 GDD Excellent fit

Sunflower Planting Timeline — Haywood County, TN

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 8 Apr 8 – Apr 29
Harvest June 24 Jun 24 – Aug 12

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Harvest
September
October
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 8a

📆 Growing Season

211 days in Haywood County

Growing Tips for Sunflower in Haywood County

Direct sow Sunflower outdoors after April 01 in Haywood 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 Haywood County, TN?

Haywood County is in Zone 8a with an average last frost of April 1. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Haywood County, TN?

Haywood County, Tennessee is in USDA Hardiness Zone 8a. The average last spring frost is April 1 and first fall frost is October 29.

🌱

Your Haywood County Garden Planner — Free

A 24-page printable planner built for Haywood County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Haywood County, TN. 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.