When to plant Corn in Thayer,
Corn planted in Thayer between April 22 and May 13 matures in 100 days — well before the October 17 first frost.
When to Plant Corn in Thayer, IL
Top priorities for Thayer, IL gardeners in June
June is a pivotal month for Thayer, IL gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Bring in the corn
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
To set up a strong July, finish these tasks
- First harvests: corn
Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.
Thayer, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.
At an elevation of 1,204 feet, Sangamon County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Corn during the growing season.
Thayer Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Corn 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 Thayer
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Corn's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Sangamon County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Corn will thrive.
How to Plant Corn
Succession Planting Corn
Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.
Corn Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Corn
Corn 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 | Corn Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4.5" | 2" | 💧 Light watering |
| May | 6.5" | 4.5" | 2" | 💧 Light watering |
| Jun | 6.5" | 5.8" | 0.7" | 💧 Light watering |
| Jul | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Aug | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Sep | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Oct | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Sangamon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn 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.
Corn Planting Timeline — Thayer, IL
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 22 | Apr 22 – May 13 |
| Harvest | June 24 | Jun 24 – Aug 19 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | Harvest |
| 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
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
185 days in Sangamon County
Growing Tips for Corn in Thayer
Direct sow Corn outdoors after April 15 in Sangamon County when soil has warmed and frost danger has passed.
Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Corn in Other Locations
When should I plant Corn in Thayer, ?
In Thayer, , plant Corn after the last frost (around April 15) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Thayer, for Corn?
Thayer sits in USDA Zone 6a. Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Corn grow in Thayer's climate?
Yes — Corn grows well in Thayer's temperate climate. Thayer averages a 185-day frost-free season, with last frost around April 15 and first frost around October 17.
Your Sangamon County Garden Planner — Free
A 22-page printable planner built for Sangamon 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.