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When to Plant Sunflower in Brown County, NE

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.

Brown County, Nebraska is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 833 feet, Brown County receives approximately 25.3 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Sunflower to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Brown County, NE (Zone 5b) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7

Brown County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.1

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 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 2.8" 1.5" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular 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 (May–Oct in Brown County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunflower Planting Timeline — Brown County, NE

Sunflower Planting Calendar

Activity When Date Range
Start Indoors April 19 Apr 19 – May 3
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 17 May 17 – Jun 7
Bloom August 9 Aug 9 – Oct 25

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Direct Sow
July
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 5b

📆 Growing Season

150 days in Brown County

Growing Tips for Brown 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 Brown County, NE?

Brown County is in Zone 5b with an average last frost of May 10. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brown County, NE?

Brown County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 7.

🌱

Your Brown County Garden Planner — Free

A 22-page printable planner built for Brown County (Zone 5b). 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 Brown County, NE. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.