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When to Plant Sweet Potatoes in Baker County, OR

Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Baker County, Oregon is in USDA Zone 5b. The average last spring frost is May 30 and the first fall frost is September 12, giving you a growing season of approximately 105 days.

At an elevation of 1,398 feet, Baker County receives approximately 16.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Sweet Potatoes during the growing season. With low rainfall, drip irrigation is essential for growing Sweet Potatoes successfully. Mulch heavily to conserve soil moisture.

Baker County, OR (Zone 5b) Short season
105 days
Last Spring Frost May 30
105 growing days
First Fall Frost September 12

Baker County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 24 Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 13 🍅 Harvest: Sep 12 – Oct 31
Safe Start (90%) ✗ May not fit
Start indoors: Apr 24 Transplant: Jul 3 🍅 Harvest: Oct 2 – Nov 20

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 Baker County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (5.3โ€“6.5) overlaps with Sweet Potatoes's range (5.5โ€“6.5), though not a perfect match.

Soil Texture

The silt loam soil in Baker County is excellent for Sweet Potatoes โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is excellent (4.8%) โ€” Sweet Potatoes will thrive.

How to Plant Sweet Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 583 gal / 100 sq ft

Monthly Watering Guide for Sweet Potatoes

Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan โ€” 2.3" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 1.1" 0" โ„๏ธ Dormant
May 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Jun 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Jul 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Aug 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Sep 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Oct โ€” 1.6" 0" โ„๏ธ Dormant
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 3.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Baker County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sweet Potatoes 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.

Sweet Potatoes needs ~1,522 GDD — county provides 1,522 GDD Tight fit

Sweet Potatoes Planting Timeline โ€” Baker County, OR

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 โ€“ Apr 18
Transplant Outdoors June 13 Jun 13 โ€“ Jun 27
Direct Sow June 6 Jun 6 โ€“ Jun 27
Harvest September 12 Sep 12 โ€“ Oct 31

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

105 days in Baker County

Growing Tips for Sweet Potatoes in Baker County

Direct sow Sweet Potatoes outdoors after May 30 in Baker County when soil has warmed and frost danger has passed.

Your 105.0-day growing season in Baker County is tight for Sweet Potatoes (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Baker County receives only 17" of rain annually. Sweet Potatoes needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Baker County, OR?

Baker County is in Zone 5b with an average last frost of May 30. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Baker County, OR?

Baker County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is May 30 and first fall frost is September 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Baker County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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