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When to plant Sunflower in Barton County, KS

Plant Sunflower in Barton County, when soil hits 50°F — usually April 20. Continue planting through May 11 for the spring crop.

When to Plant Sunflower in Barton County, KS

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.

Barton County, Kansas is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 16, giving you a growing season of approximately 179 days.

At an elevation of 638 feet, Barton County receives approximately 25.9 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Barton County, KS (Zone 6b) Moderate season
179 days
Last Spring Frost April 20
179 growing days
First Fall Frost October 16

Barton County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.3

Drainage

Well Drained

Monthly Watering Guide for Sunflower

Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 1.6" 2.7" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Barton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunflower Planting Timeline — Barton County, KS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 20 Apr 20 – May 11
Bloom July 13 Jul 13 – Oct 12

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

179 days in Barton County

Growing Tips for Barton County

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 Barton County, KS?

Barton County is in Zone 6b with an average last frost of April 20. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barton County, KS?

Barton County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 16.

When should I plant Sunflower in Barton County, KS?

In Barton County, KS, plant Sunflower after the last frost (around April 20) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Barton County, KS for Sunflower?

Barton County sits in USDA Zone 6b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Barton County's climate?

Yes — Sunflower grows well in Barton County's temperate climate. Barton County averages a 179-day frost-free season, with last frost around April 20 and first frost around October 16.

🌱

Your Barton County Garden Planner — Free

A 22-page printable planner built for Barton County (Zone 6b). 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 Barton County, KS. Local conditions may vary. Last updated: July 2026.

Sources & credits

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