Blog

When to Plant Sunflower in Pierce County, NE

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.

Pierce County, Nebraska is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.

At an elevation of 658 feet, Pierce County receives approximately 23.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Sunflower to ensure they mature before fall.

Pierce County, NE (Zone 4b) Moderate season
159 days
Last Spring Frost April 30
159 growing days
First Fall Frost October 6

Pierce County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Feb 19 Transplant: May 14 🍅 Harvest: Jul 23 – Sep 10
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Feb 26 Transplant: May 21 🍅 Harvest: Jul 30 – Sep 17
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Mar 14 Transplant: Jun 6 🍅 Harvest: Aug 15 – Oct 3

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 Pierce County

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

Soil pH

Your soil pH (6.8โ€“7.2) is within Sunflower's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Pierce County is excellent for Sunflower โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

2
successive plantings in your 159-day season

Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr 2.2" 2.3" 0" โœ… Rainfall sufficient
May 2.2" 3" 0" โœ… Rainfall sufficient
Jun 2.2" 3.6" 0" โœ… Rainfall sufficient
Jul 2.2" 3.2" 0" โœ… Rainfall sufficient
Aug 2.2" 3.1" 0" โœ… Rainfall sufficient
Sep 2.2" 2.2" 0" โœ… Rainfall sufficient
Oct 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Pierce County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,105 GDD — county provides 2,067 GDD Excellent fit

Sunflower Planting Timeline โ€” Pierce County, NE

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors May 21 May 21 โ€“ Jun 4
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest July 30 Jul 30 โ€“ Sep 17

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

159 days in Pierce County

Growing Tips for Sunflower in Pierce County

Direct sow Sunflower outdoors after April 30 in Pierce 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.

Pierce County receives only 24" of rain annually. Sunflower needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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 Pierce County, NE?

Pierce County is in Zone 4b with an average last frost of April 30. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pierce County, NE?

Pierce County, Nebraska is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pierce County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pierce County, NE. Local conditions may vary. Last updated: April 2026.