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When to Plant Sunflower in Richland Parish, LA

Richland Parish, Louisiana Zone 8b May

Your May game plan for Richland Parish, Louisiana

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 9
Avg. first frost November 14
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
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.

Richland Parish, Louisiana is in USDA Zone 8b. The average last spring frost is March 9 and the first fall frost is November 14, giving you a growing season of approximately 250 days.

At an elevation of 341 feet, Richland Parish receives approximately 59.8 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Sunflower may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Richland Parish, LA (Zone 8b) Long season
250 days
Last Spring Frost March 9
250 growing days
First Fall Frost November 14
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Richland Parish Soil Profile

Soil Type

Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Jan 12 Transplant: Mar 16 🍅 Harvest: May 25 – Jul 13
Recommended (50%) ✓ Fits season (117 days to spare)
Start indoors: Jan 19 Transplant: Mar 23 🍅 Harvest: Jun 1 – Jul 20
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Jun 30 – Aug 18

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 Richland Parish

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

Soil pH

Your soil pH (6.2–7.0) is within Sunflower's preferred range (6.0–7.5).

Soil Texture

The loam soil in Richland Parish is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is moderate (2.5%). 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 250-day season

Sow every 8 weeks. Last sowing by Aug 06 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 5.6" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 2.2" 6.2" 0" ✅ Rainfall sufficient
Apr 2.2" 4.2" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 5.2" 0" ✅ Rainfall sufficient
Jul 2.2" 6.5" 0" ✅ Rainfall sufficient
Aug 2.2" 6.2" 0" ✅ Rainfall sufficient
Sep 2.2" 5.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.6" 0" ✅ Rainfall sufficient
Nov 2.2" 4.2" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Richland Parish). 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 ~1,806 GDD — county provides 5,312 GDD Excellent fit

Sunflower Planting Timeline — Richland Parish, LA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 19 Jan 19 – Feb 2
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 16 Mar 16 – Apr 6
Harvest June 1 Jun 1 – Jul 20

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
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: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

250 days in Richland Parish

Growing Tips for Sunflower in Richland Parish

Direct sow Sunflower outdoors after March 09 in Richland Parish 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 Richland Parish, LA?

Richland Parish is in Zone 8b with an average last frost of March 9. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland Parish, LA?

Richland Parish, Louisiana is in USDA Hardiness Zone 8b. The average last spring frost is March 9 and first fall frost is November 14.

🌱

Your Richland Parish Garden Planner — Free

A 24-page printable planner built for Richland Parish (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 Richland Parish, LA. 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.