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When to Plant Butternut Squash in Sherman County, OR

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.

Sherman County, Oregon is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 862 feet, Sherman County receives approximately 15 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Butternut Squash during the growing season. With low rainfall, drip irrigation is essential for growing Butternut Squash successfully. Mulch heavily to conserve soil moisture.

Sherman County, OR (Zone 6a) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Sherman County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Start indoors: Mar 3 Transplant: Apr 21 🍅 Harvest: Jul 21 – Aug 25
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 10 Transplant: Apr 28 🍅 Harvest: Jul 28 – Sep 1
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Aug 15 – Sep 19

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 Sherman County

How your county's soil matches Butternut Squash's growing requirements.

Soil pH

Your soil pH (5.7โ€“6.3) overlaps with Butternut Squash's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Sherman County is excellent for Butternut Squash โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) โ€” Butternut Squash will thrive.

How to Plant Butternut Squash

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,260 gal / 100 sq ft

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 โ€” 2.2" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr 4.8" 1.2" 3.6" ๐Ÿšฟ Regular watering
May 4.8" 0.8" 4" ๐Ÿšฟ Regular watering
Jun 4.8" 0.5" 4.3" ๐Ÿšฟ Regular watering
Jul 4.8" 0.2" 4.6" ๐Ÿšฟ Regular watering
Aug 4.8" 0.3" 4.5" ๐Ÿšฟ Regular watering
Sep 4.8" 0.5" 4.3" ๐Ÿšฟ Regular watering
Oct 4.8" 1.3" 3.5" ๐Ÿšฟ Regular watering
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 2.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Sherman County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~1,633 GDD — county provides 3,115 GDD Excellent fit

Butternut Squash Planting Timeline โ€” Sherman County, OR

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest July 28 Jul 28 โ€“ Sep 1

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

85โ€“110 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

186 days in Sherman County

Growing Tips for Butternut Squash in Sherman County

Direct sow Butternut Squash outdoors after April 14 in Sherman County when soil has warmed and frost danger has passed.

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.

Sherman County receives only 15" of rain annually. Butternut Squash needs consistent moisture โ€” 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

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Sherman County, OR?

Sherman County is in Zone 6a with an average last frost of April 14. Plan your Butternut Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sherman County, OR?

Sherman County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sherman County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sherman County, OR. Local conditions may vary. Last updated: April 2026.