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When to Plant Potatoes in Aroostook County, ME

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Aroostook County, Maine is in USDA Zone 3b. The average last spring frost is May 18 and the first fall frost is September 24, giving you a growing season of approximately 129 days.

At an elevation of 314 feet, Aroostook County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78ยฐF, so choose short-season varieties of Potatoes to ensure they mature before fall.

Aroostook County, ME (Zone 3b) Short season
129 days
Last Spring Frost May 18
129 growing days
First Fall Frost September 24

Aroostook County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 10 Transplant: Jun 2 🍅 Harvest: Aug 11 – Oct 6
Recommended (50%) ✗ May not fit
Start indoors: Mar 16 Transplant: Jun 8 🍅 Harvest: Aug 17 – Oct 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 22 🍅 Harvest: Aug 31 – Oct 26

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 Aroostook County

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

Soil pH

Your soil pH (4.9โ€“6.3) overlaps with Potatoes's range (5.0โ€“6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Potatoes.

How to Plant Potatoes

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

Succession Planting Potatoes

2
successive plantings in your 129-day season

Sow every 8 weeks. Last sowing by May 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Potatoes

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 Potatoes Needs Rainfall You Supplement Action
Jan โ€” 2.8" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar โ€” 3.3" 0" โ„๏ธ Dormant
Apr โ€” 3.5" 0" โ„๏ธ Dormant
May 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Jun 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jul 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Aug 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Sep 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Oct โ€” 3.2" 0" โ„๏ธ Dormant
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 3" 0" โ„๏ธ Dormant

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

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.

Potatoes needs ~808 GDD — county provides 1,096 GDD Excellent fit

Potatoes Planting Timeline โ€” Aroostook County, ME

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 โ€“ Mar 30
Transplant Outdoors June 8 Jun 8 โ€“ Jun 22
Direct Sow June 1 Jun 1 โ€“ Jun 22
Harvest August 17 Aug 17 โ€“ Oct 12

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“120 days

๐Ÿงช Soil pH

Needs 5โ€“6.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 3b

๐Ÿ“† Growing Season

129 days in Aroostook County

Growing Tips for Potatoes in Aroostook County

Direct sow Potatoes outdoors after May 18 in Aroostook County when soil has warmed and frost danger has passed.

Your 129.0-day growing season in Aroostook County is tight for Potatoes (70.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Recommended Potatoes Varieties for Aroostook County

Early-maturing potatoes for your season

Yukon Gold (65d) Red Norland (70d) Irish Cobbler (70d)

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Potatoes in Aroostook County, ME?

Aroostook County is in Zone 3b with an average last frost of May 18. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Aroostook County, ME?

Aroostook County, Maine is in USDA Hardiness Zone 3b. The average last spring frost is May 18 and first fall frost is September 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Aroostook County gardeners in Zone 3b 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 Aroostook County, ME. Local conditions may vary. Last updated: April 2026.