When to Plant Watermelon in Edgar County, IL
This month in Edgar County, Illinois
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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Set out watermelon seedlings
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Begin indoor sowing: watermelon
Your window is short. These crops want several weeks of indoor growth before they go outside.
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.
Edgar County, Illinois is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 17, giving you a growing season of approximately 182 days.
At an elevation of 1,272 feet, Edgar County receives approximately 41.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Watermelon to ensure they mature before fall.
Edgar County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
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 Edgar County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Edgar County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Watermelon will thrive.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jul 09 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Watermelon
Watermelon needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watermelon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| May | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Jun | 6.5" | 5.5" | 1" | 💧 Light watering |
| Jul | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Aug | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Sep | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Oct | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Edgar County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watermelon 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.
Watermelon Planting Timeline — Edgar County, IL
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | July 11 | Jul 11 – Aug 29 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
182 days in Edgar County
Growing Tips for Watermelon in Edgar County
Direct sow Watermelon outdoors after April 18 in Edgar County when soil has warmed and frost danger has passed.
Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
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 Edgar County, IL?
Edgar County is in Zone 6a with an average last frost of April 18. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Edgar County, IL?
Edgar County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 17.
Your Edgar County Garden Planner — Free
A 24-page printable planner built for Edgar County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.