When to plant Watermelon in Winnebago County, IL
Watermelon planted in Winnebago County between May 3 and May 24 matures in 70–100 days — well before the October 12 first frost.
When to Plant Watermelon in Winnebago County, IL
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
Winnebago County, Illinois is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.
At an elevation of 1,318 feet, Winnebago County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watermelon during the growing season.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
How Much Watermelon to Grow
For a family of 4, plant approximately 4 watermelon plants in about 8 sq ft. In Winnebago County's 169-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Watermelon Planting Timeline — Winnebago County, IL
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 3 | May 3 – May 24 |
| Harvest | July 19 | Jul 19 – Sep 6 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
169 days in Winnebago County
Growing Tips for Winnebago County
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Winnebago County, IL?
Winnebago County is in Zone 5b with an average last frost of April 26. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Winnebago County, IL?
Winnebago County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 12.
When should I plant Watermelon in Winnebago County, IL?
In Winnebago County, IL, plant Watermelon after the last frost (around April 26) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Winnebago County, IL for Watermelon?
Winnebago County sits in USDA Zone 5b. Watermelon grows reliably in zones 4a through 11b, so it's a good fit here.
Can Watermelon grow in Winnebago County's climate?
Yes — Watermelon grows well in Winnebago County's temperate climate. Winnebago County averages a 169-day frost-free season, with last frost around April 26 and first frost around October 12.
Your Winnebago County Garden Planner — Free
A 22-page printable planner built for Winnebago 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.