When to Plant Corn in Edmunds County, SD
Your May gardening checklist
May is a pivotal month for Edmunds County, South Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Direct-sow corn
These tolerate cool soil, so you're not gambling by sowing now.
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.
Edmunds County, South Dakota is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is September 28, giving you a growing season of approximately 141 days.
At an elevation of 935 feet, Edmunds County receives approximately 33.7 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Corn to ensure they mature before fall.
Edmunds County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.6
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 Edmunds County
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.4–7.6) overlaps with Corn's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Edmunds County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Corn.
How to Plant Corn
Succession Planting Corn
Sow every 6.9 weeks. Last sowing by Jun 20 to harvest before frost.
Plant 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 | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 6.5" | 4.5" | 2" | 💧 Light watering |
| Jun | 6.5" | 6.1" | 0.4" | 💧 Light watering |
| Jul | 6.5" | 4.5" | 2" | 💧 Light watering |
| Aug | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Sep | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Oct | — | 2.1" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Edmunds 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 — Edmunds County, SD
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | July 26 | Jul 26 – Sep 20 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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 4b
📆 Growing Season
141 days in Edmunds County
Growing Tips for Corn in Edmunds County
Direct sow Corn outdoors after May 10 in Edmunds 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
Frequently Asked Questions
When should I plant Corn in Edmunds County, SD?
Edmunds County is in Zone 4b with an average last frost of May 10. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Edmunds County, SD?
Edmunds County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is September 28.
Your Edmunds County Garden Planner — Free
A 24-page printable planner built for Edmunds 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.