When to plant Butternut Squash in Fallon County, MT
Plant Butternut Squash in Fallon County, between June 3 and June 24 — the only viable window. Zone 4b's short season (123 frost-free days) rules out a fall crop.
When to Plant Butternut Squash in Fallon County, MT
What to do in June
Welcome to June in Zone 4b. These are the moves that will have the biggest impact on your growing season.
Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.
Fallon County, 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 6,441 feet, Fallon County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Butternut Squash successfully. Mulch heavily to conserve soil moisture.
Fallon County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.3
Drainage
Well Drained
Butternut Squash 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 Fallon County
How your county's soil matches Butternut Squash's growing requirements.
Soil pH
Your soil pH (6.2–8.3) is more alkaline than Butternut Squash prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Fallon County is excellent for Butternut Squash — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Butternut Squash.
How to Plant Butternut Squash
Butternut Squash Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Butternut Squash
Butternut Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Butternut Squash Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 4.8" | 2.7" | 2.1" | 💧 Light watering |
| Jun | 4.8" | 1.4" | 3.4" | 🚿 Regular watering |
| Jul | 4.8" | 1.6" | 3.2" | 🚿 Regular watering |
| Aug | 4.8" | 1.9" | 2.9" | 🚿 Regular watering |
| Sep | 4.8" | 1.6" | 3.2" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Fallon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Butternut Squash 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.
Butternut Squash Planting Timeline — Fallon County, MT
Butternut Squash Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | June 10 | Jun 10 – Jun 24 |
| Direct Sow | June 3 | Jun 3 – Jun 24 |
| Harvest | September 9 | Sep 9 – Oct 14 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | — |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.1"/week · 1-2 times/week
📅 Days to Maturity
85–110 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 4b
📆 Growing Season
123 days in Fallon County
Growing Tips for Butternut Squash in Fallon County
Direct sow Butternut Squash outdoors after May 20 in Fallon County when soil has warmed and frost danger has passed.
Your 123.0-day growing season in Fallon County is tight for Butternut Squash (85.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Butternut Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
Fallon County receives only 20" of rain annually. Butternut Squash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Butternut Squash in Other Locations
Frequently Asked Questions
When should I plant Butternut Squash in Fallon County, MT?
Fallon County is in Zone 4b with an average last frost of May 20. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fallon County, MT?
Fallon County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 20.
When should I plant Butternut Squash in Fallon County, MT?
In Fallon County, MT, plant Butternut Squash 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 Fallon County, MT for Butternut Squash?
Fallon County sits in USDA Zone 4b. Butternut Squash grows reliably in zones 3a through 11b, so it's a good fit here.
Can Butternut Squash grow in Fallon County's climate?
Yes — Butternut Squash grows well in Fallon County's temperate climate. Fallon County averages a 123-day frost-free season, with last frost around May 20 and first frost around September 20.
Your Fallon County Garden Planner — Free
A 22-page printable planner built for Fallon 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.