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When to Plant Sunflower in Jefferson Davis County, MS

Jefferson Davis County, Mississippi Zone 8b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jefferson Davis County, Mississippi.

Avg. last frost March 8
Avg. first frost November 19
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Collect sunflower at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Before June arrives, get these ready
  • 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.

Jefferson Davis County, Mississippi is in USDA Zone 8b. The average last spring frost is March 8 and the first fall frost is November 19, giving you a growing season of approximately 256 days.

At an elevation of 126 feet, Jefferson Davis County receives approximately 59.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°F, providing good warmth for Sunflower during the growing season. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Jefferson Davis County, MS (Zone 8b) Long season
256 days
Last Spring Frost March 8
256 growing days
First Fall Frost November 19
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Jefferson Davis County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Jan 11 Transplant: Mar 15 🍅 Harvest: May 24 – Jul 12
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Jan 18 Transplant: Mar 22 🍅 Harvest: May 31 – Jul 19
Safe Start (90%) ✓ Fits season (118 days to spare)
Start indoors: Feb 6 Transplant: Apr 10 🍅 Harvest: Jun 19 – Aug 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 Jefferson Davis County

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

Soil pH

Your soil pH (5.6–6.4) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Sunflower.

How to Plant Sunflower

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

Succession Planting Sunflower

4
successive plantings in your 256-day season

Sow every 8 weeks. Last sowing by Aug 11 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 5.3" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 2.2" 6" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.7" 0" ✅ Rainfall sufficient
Aug 2.2" 6.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 3.9" 0" ✅ Rainfall sufficient
Dec 5.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Jefferson Davis 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 5,056 GDD Excellent fit

Sunflower Planting Timeline — Jefferson Davis County, MS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 18 Jan 18 – Feb 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 31 May 31 – Jul 19

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August
September
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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

256 days in Jefferson Davis County

Growing Tips for Sunflower in Jefferson Davis County

Direct sow Sunflower outdoors after March 08 in Jefferson Davis County when soil has warmed and frost danger has passed.

With Jefferson Davis County's clay soil (31% clay), work in 3-4 inches of compost before planting Sunflower. Avoid tilling when soil is wet to prevent compaction.

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 Jefferson Davis County, MS?

Jefferson Davis County is in Zone 8b with an average last frost of March 8. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson Davis County, MS?

Jefferson Davis County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 8 and first fall frost is November 19.

🌱

Your Jefferson Davis County Garden Planner — Free

A 24-page printable planner built for Jefferson Davis County (Zone 8b). 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 Jefferson Davis County, MS. 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.