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When to Plant Sunflower in Cheyenne County, NE

Cheyenne County, Nebraska Zone 5b May

Your May planting checklist for Cheyenne County, Nebraska

We've pulled the most time-sensitive tasks for Cheyenne County, Nebraska this May and put them front and centre. Tackle them in order.

Avg. last frost May 11
Avg. first frost October 4
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Plant out sunflower

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Put sunflower seeds straight in the ground

    Your soil is 55°F — warm enough for these to germinate without babying.

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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.

Cheyenne County, Nebraska is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is October 4, giving you a growing season of approximately 146 days.

At an elevation of 1,108 feet, Cheyenne County receives approximately 26.9 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Sunflower to ensure they mature before fall.

Cheyenne County, NE (Zone 5b) Short season
146 days
Last Spring Frost May 11
146 growing days
First Fall Frost October 4

Cheyenne County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Jul 25 – Sep 12
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Mar 16 Transplant: May 25 🍅 Harvest: Aug 3 – Sep 21
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Mar 25 Transplant: Jun 3 🍅 Harvest: Aug 12 – Sep 30

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 Cheyenne County

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

Soil pH

Your soil pH (6.4–7.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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 146-day season

Sow every 8 weeks. Last sowing by Jun 26 to harvest before frost.

Plant Water Budget

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

Water stress score is 8/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 2.2" 3.1" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 2.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 1.9" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cheyenne 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 ~1,105 GDD — county provides 1,898 GDD Excellent fit

Sunflower Planting Timeline — Cheyenne County, NE

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors May 25 May 25 – Jun 8
Direct Sow May 18 May 18 – Jun 8
Harvest August 3 Aug 3 – Sep 21

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October
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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

146 days in Cheyenne County

Growing Tips for Sunflower in Cheyenne County

Direct sow Sunflower outdoors after May 11 in Cheyenne 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.

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 Cheyenne County, NE?

Cheyenne County is in Zone 5b with an average last frost of May 11. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cheyenne County, NE?

Cheyenne County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is October 4.

🌱

Your Cheyenne County Garden Planner — Free

A 24-page printable planner built for Cheyenne 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.

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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 Cheyenne County, NE. Local conditions may vary. Last updated: May 2026.

Sources & credits

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