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When to plant Sunflower in Barber County, KS

Barber County's climate puts the Sunflower spring window between April 15 and May 6. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Sunflower in Barber County, KS

Barber County, Kansas Zone 7a June

Barber County, Kansas gardeners: here's your June plan

Welcome to June in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 15
Avg. first frost October 24
Soil temp (4") 74°F
Watering Moderate
Pest pressure High
Daylight 14.5 hrs
Looking ahead to July
  • 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.

Barber County, Kansas is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 964 feet, Barber County receives approximately 20.6 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
Barber County, KS (Zone 7a) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Barber County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.1

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 19 Transplant: Apr 9 🌸 Bloom: Jul 2 – Oct 8
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: Mar 25 Transplant: Apr 15 🌸 Bloom: Jul 8 – Oct 14
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Apr 7 Transplant: Apr 28 🌸 Bloom: Jul 21 – Oct 27

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 Barber County

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

Soil pH

Your soil pH (6.6–7.1) is within Sunflower's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Sunflower will thrive.

How to Plant Sunflower

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

Succession Planting Sunflower

3
successive plantings in your 192-day season

Sow every 8 weeks. Last sowing by Jul 16 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 101 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 0.5" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.2" 2.1" 0.1" 💧 Light watering
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 3.2" 0" ✅ Rainfall sufficient
Jul 2.2" 2.4" 0" ✅ Rainfall sufficient
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 0.6" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Barber 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 ~1,488 GDD — county provides 3,360 GDD Excellent fit

Sunflower Planting Timeline — Barber County, KS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 15 Apr 15 – May 6
Bloom July 8 Jul 8 – Oct 14

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 Direct Sow
June
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

192 days in Barber County

Growing Tips for Sunflower in Barber County

Direct sow Sunflower outdoors after April 15 in Barber County 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.

Barber County receives only 21" of rain annually. Sunflower needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Barber County, KS?

Barber County is in Zone 7a with an average last frost of April 15. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barber County, KS?

Barber County, Kansas is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 24.

When should I plant Sunflower in Barber County, KS?

In Barber County, KS, plant Sunflower after the last frost (around April 15) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Barber County, KS for Sunflower?

Barber County sits in USDA Zone 7a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Barber County's climate?

Yes — Sunflower grows well in Barber County's temperate climate. Barber County averages a 192-day frost-free season, with last frost around April 15 and first frost around October 24.

🌱

Your Barber County Garden Planner — Free

A 22-page printable planner built for Barber County (Zone 7a). 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 Barber County, KS. 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.