When to Plant Sunflower in Seward County, NE
This month in Seward County, Nebraska
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Harden off and plant sunflower
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
To set up a strong June, finish these tasks
- Starting indoors: sunflower
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.
Seward County, Nebraska is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.
At an elevation of 527 feet, Seward County receives approximately 24.2 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.
Seward County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Seward County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.4–7.2) is within Sunflower's preferred range (6.0–7.5).
Soil Texture
The loam soil in Seward County is excellent for Sunflower — 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
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 05 to harvest before frost.
Plant Water Budget
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Seward 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 Planting Timeline — Seward County, NE
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | July 14 | Jul 14 – Sep 1 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| 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: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
175 days in Seward County
Growing Tips for Sunflower in Seward County
Direct sow Sunflower outdoors after April 21 in Seward 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.
Seward County receives only 24" of rain annually. Sunflower needs consistent moisture — 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Seward County, NE?
Seward County is in Zone 5b with an average last frost of April 21. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Seward County, NE?
Seward County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 13.
Your Seward County Garden Planner — Free
A 24-page printable planner built for Seward 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.