When to plant Corn in Grass Range, MT
Grass Range's short 123-day growing season means one Corn planting between June 3 and June 24. No fall crop in Zone 4b.
When to Plant Corn in Grass Range, MT
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.
Grass Range, Montana is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.
At an elevation of 6,957 feet, Fergus County receives approximately 12 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Corn to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Corn successfully. Mulch heavily to conserve soil moisture.
Grass Range Soil Profile
Soil Type
Loam
Soil pH
6.4-8
Drainage
Well Drained
How Much Corn to Grow
For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In Fergus County's 123-day season, you'll have plenty of time for a full harvest. Plan your garden layout →
Monthly Watering Guide for Corn
Corn needs approximately 1 inches of water per week (4.3" 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 | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jun | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Jul | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Aug | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Sep | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Fergus County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn Planting Timeline — Grass Range, MT
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | June 3 | Jun 3 – Jun 24 |
| Harvest | August 5 | Aug 5 – Sep 30 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
123 days in Fergus County
Growing Tips for Grass Range
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 Grass Range, MT?
In Grass Range, MT, plant Corn after the last frost (around May 20) and before the first frost (around September 20). Best results when soil holds above 50°F.
What growing zone is Grass Range, MT for Corn?
Grass Range sits in USDA Zone 4b. Corn grows reliably in zones 3a through 11b, so it's a good fit here.
Can Corn grow in Grass Range's climate?
Yes — Corn grows well in Grass Range's temperate climate. Grass Range averages a 123-day frost-free season, with last frost around May 20 and first frost around September 20.
Your Fergus County Garden Planner — Free
A 22-page printable planner built for Fergus 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.