When to Plant Sunflower in Fond du Lac County, WI
Top priorities for Fond du Lac County, Wisconsin gardeners in April
April is a pivotal month for Fond du Lac County, Wisconsin gardens. Focus on these tasks first and you'll set up the rest of the season for success.
A few tasks this April that'll pay off in May
- Transplants going out: sunflower
- Direct-sowing: 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.
Fond du Lac County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 27 and the first fall frost is October 14, giving you a growing season of approximately 170 days.
At an elevation of 713 feet, Fond du Lac County receives approximately 32.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Fond du Lac County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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 Fond du Lac County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.2–7.2) is within Sunflower's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Fond du Lac County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Sunflower will thrive.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 06 to harvest before frost.
Plant Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Fond du Lac 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 — Fond du Lac County, WI
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | July 27 | Jul 27 – Sep 14 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| 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 4b
📆 Growing Season
170 days in Fond du Lac County
Growing Tips for Sunflower in Fond du Lac County
Direct sow Sunflower outdoors after April 27 in Fond du Lac 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Fond du Lac County, WI?
Fond du Lac County is in Zone 4b with an average last frost of April 27. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fond du Lac County, WI?
Fond du Lac County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 27 and first fall frost is October 14.
Your Fond du Lac County Garden Planner — Free
A 24-page printable planner built for Fond du Lac County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.