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When to Plant Sunflower in Kaufman County, TX

Kaufman County, Texas Zone 8b May

Your May planting checklist for Kaufman County, Texas

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 12
Avg. first frost November 18
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
June prep starts now
  • 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.

Kaufman County, Texas is in USDA Zone 8b. The average last spring frost is March 12 and the first fall frost is November 18, giving you a growing season of approximately 251 days.

At an elevation of 144 feet, Kaufman County receives approximately 59.6 inches of rainfall annually with predominantly clay 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.

Kaufman County, TX (Zone 8b) Long season
251 days
Last Spring Frost March 12
251 growing days
First Fall Frost November 18
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Kaufman County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Jan 14 Transplant: Mar 18 🍅 Harvest: May 27 – Jul 15
Recommended (50%) ✓ Fits season (118 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jun 4 – Jul 23
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jul 1 – Aug 19

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 Kaufman County

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

Soil pH

Your soil pH (6.9–8.3) is more alkaline than Sunflower prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (48% clay) in Kaufman County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

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 251-day season

Sow every 8 weeks. Last sowing by Aug 10 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
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 1.4" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.2" 3.9" 0" ✅ Rainfall sufficient
Apr 2.2" 6.2" 0" ✅ Rainfall sufficient
May 2.2" 8" 0" ✅ Rainfall sufficient
Jun 2.2" 10.8" 0" ✅ Rainfall sufficient
Jul 2.2" 7.5" 0" ✅ Rainfall sufficient
Aug 2.2" 6.9" 0" ✅ Rainfall sufficient
Sep 2.2" 5.5" 0" ✅ Rainfall sufficient
Oct 2.2" 4.1" 0" ✅ Rainfall sufficient
Nov 2.2" 1.8" 0.4" 💧 Light watering
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Kaufman 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 4,957 GDD Excellent fit

Sunflower Planting Timeline — Kaufman County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors March 26 Mar 26 – Apr 9
Direct Sow March 19 Mar 19 – Apr 9
Harvest June 4 Jun 4 – Jul 23

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: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

251 days in Kaufman County

Growing Tips for Sunflower in Kaufman County

Direct sow Sunflower outdoors after March 12 in Kaufman County when soil has warmed and frost danger has passed.

With Kaufman County's clay soil (48% 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 Kaufman County, TX?

Kaufman County is in Zone 8b with an average last frost of March 12. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kaufman County, TX?

Kaufman County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 12 and first fall frost is November 18.

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Your Kaufman County Garden Planner — Free

A 24-page printable planner built for Kaufman 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 Kaufman County, TX. 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.