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When to Plant Sunflower in Jeff Davis County, TX

Jeff Davis County, Texas Zone 8a June

June in Jeff Davis County, Texas — your action list

We've pulled the most time-sensitive tasks for Jeff Davis County, Texas this June and put them front and centre. Tackle them in order.

Avg. last frost April 3
Avg. first frost November 1
Soil temp (4") 67°F
Watering High
Pest pressure High
Daylight 14 hrs
  1. Basket week: sunflower

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

July prep starts now
  • 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.

Jeff Davis County, Texas is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is November 1, giving you a growing season of approximately 212 days.

At an elevation of 4,298 feet, Jeff Davis County receives approximately 52.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Jeff Davis County, TX (Zone 8a) Long season
212 days
Last Spring Frost April 3
212 growing days
First Fall Frost November 1

Jeff Davis County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.7

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Feb 27 Transplant: Mar 13 🌸 Bloom: Jun 5 – Oct 9
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Mar 13 Transplant: Mar 27 🌸 Bloom: Jun 19 – Oct 23
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Apr 1 Transplant: Apr 15 🌸 Bloom: Jul 8 – Nov 11

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 Jeff Davis County

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

Soil pH

Your soil pH (7.2–8.7) is more alkaline than Sunflower prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Jeff Davis County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 212-day season

Sow every 8 weeks. Last sowing by Jul 24 to harvest before frost.

Sunflower 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 3.3" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 1.3" 0.9" 💧 Light watering
Jun 2.2" 1.8" 0.4" 💧 Light watering
Jul 2.2" 8.1" 0" ✅ Rainfall sufficient
Aug 2.2" 11.6" 0" ✅ Rainfall sufficient
Sep 2.2" 6.6" 0" ✅ Rainfall sufficient
Oct 2.2" 5" 0" ✅ Rainfall sufficient
Nov 2.2" 3.1" 0" ✅ Rainfall sufficient
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Jeff 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 ~1,870 GDD — county provides 4,664 GDD Excellent fit

Sunflower Planting Timeline — Jeff Davis County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 27 Mar 27 – Apr 17
Bloom June 19 Jun 19 – Oct 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Bloom
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: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

212 days in Jeff Davis County

Growing Tips for Sunflower in Jeff Davis County

Direct sow Sunflower outdoors after April 03 in Jeff Davis County when soil has warmed and frost danger has passed.

Sandy soil in Jeff Davis County dries quickly — mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Jeff Davis County, provide afternoon shade for Sunflower and water deeply in the morning.

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 Jeff Davis County, TX?

Jeff Davis County is in Zone 8a with an average last frost of April 3. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jeff Davis County, TX?

Jeff Davis County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is November 1.

🌱

Your Jeff Davis County Garden Planner — Free

A 22-page printable planner built for Jeff Davis 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.

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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 Jeff Davis County, TX. 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.