When to Plant Sunflower in Johnson 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.
Johnson County, Nebraska is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 7, giving you a growing season of approximately 166 days.
At an elevation of 658 feet, Johnson County receives approximately 21.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Sunflower during the growing season.
Johnson County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Sunflower Planting Timeline — Johnson County, NE
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | May 1 | May 1 – May 22 |
| Bloom | July 24 | Jul 24 – Oct 9 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| 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
166 days in Johnson County
Growing Tips for Johnson 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Johnson County, NE?
Johnson County is in Zone 5b with an average last frost of April 24. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, NE?
Johnson County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 7.
Your Johnson County Garden Planner — Free
A 22-page printable planner built for Johnson 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.