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Aroostook County, ME — Planting Guide

Aroostook County 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 ft, Aroostook County receives approximately 39.5 in of rainfall annually. Summer highs average 78°F with winter lows around -9°F. The predominant soil type is Silt Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 26 days year to year — ranging from May 6 in warm years to June 1 in cold years. Aroostook County scores 79/100 (Good) on the Microclimate Index.

🌡️ Zone

3b (-35°F to -30°F min)

❄️ Last Frost

May 18

🍂 First Frost

September 24

📅 Growing Season

129 days

⛰️ Elevation

314 ft

🌧️ Annual Rainfall

39.5 in

Aroostook County, ME Short season
129 days
Last Spring Frost May 18
129 growing days
First Fall Frost September 24

Monthly Watering Calendar

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 2.8" Feb 2.7" Mar 3.3" Apr 3.5" +1" May 3.3" +0.6" Jun 3.7" +0.7" Jul 3.6" +0.7" Aug 3.6" +0.4" Sep 3.9" Oct 3.2" Nov 2.9" Dec 3"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 2.8 in 9 days None
Feb 2.7 in 10 days None
Mar 3.3 in 11 days None
Apr 3.5 in 9 days None
May 3.3 in 12 days 1 in Moderate
Jun 3.7 in 10 days 0.6 in Moderate
Jul 3.6 in 9 days 0.7 in Moderate
Aug 3.6 in 10 days 0.7 in Moderate
Sep 3.9 in 8 days 0.4 in Low
Oct 3.2 in 9 days None
Nov 2.9 in 9 days None
Dec 3 in 12 days None

Annual total: 39.5 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.

Aroostook County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Frost Risk Probability

Based on 31 years of NOAA weather station data from 2 stations

Too early frost risk Safe to Plant May 18 → Sep 24 129 frost-free days Protect crops frost returns May Jun Jul Aug Sep Oct Nov Safe: Jun 1 Protect by: Oct 5

Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.

How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.

Planting Strategy Last Spring Frost First Fall Frost Frost-Free Days
Conservative (safest) Jun 1 Oct 5 126 days
Cautious May 23 Sep 30 130 days
Average year May 18 Sep 24 129 days
Optimistic May 12 Sep 18 129 days
Aggressive (risky) May 6 Sep 14 131 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±26 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

Gardening Difficulty Score

79 Good
Frost Timing Risk
10.0/10
Drought Risk
1.5/10
Soil Difficulty
0.0/10
Altitude Challenge
0.0/10
Climate Shift
1.0/10
Rainfall Challenge
0.0/10

Aroostook County offers good growing conditions. A little planning around frost dates goes a long way.

Zone 3b Frost Countdown
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Loading...
Last Frost: May 18 First Frost: Sep 24

Local Gardening Help in Aroostook County

Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Aroostook County's climate and soil.

County Extension Office

Aroostook County University of Maine Cooperative Extension Extension Office

Phone: 207-581-3188

Visit Extension Office Website →

Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.

Master Gardener Program

Free gardening help from trained volunteers

Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.

Find Master Gardeners in ME →

Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.

Soil Testing

Available through your extension office

Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.

Request a Soil Test →

Services Available in Aroostook County

Soil testing Short-season gardening Pest identification
Finding local nurseries & garden centers in Aroostook County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Aroostook County's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.

How to Find Them

Search for "nurseries near Aroostook County ME" or "garden center Aroostook County" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.

Community gardens & gardening groups

Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Aroostook County ME" or check your extension office and local parks department. Facebook groups like "Aroostook County Gardeners" or "Maine Gardening" are also excellent for local advice and plant swaps.

What to Plant After Your Harvest

After your first crops finish, use the remaining frost-free days to grow a second round.

After Carrots (harvest ends Aug 24) 31 days until frost
After Spinach (harvest ends Aug 24) 31 days until frost
After Scallions (harvest ends Aug 10) 45 days until frost
After Mustard Greens (harvest ends Aug 24) 31 days until frost
Show 6 more succession options
After Arugula (harvest ends Aug 24) 31 days until frost
After Cilantro (harvest ends Aug 24) 31 days until frost
After Turnip (harvest ends Aug 3) 52 days until frost
After Patty Pan Squash (harvest ends Aug 24) 31 days until frost
After Dill (harvest ends Aug 24) 31 days until frost
After Radish (harvest ends Jul 6) 80 days until frost

Sunlight & Day Length

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Longest Day

15.6 hours

Summer solstice daylight

Shortest Day

8.4 hours

Winter solstice daylight

Peak Sun Hours

8.8 hr/day peak (summer)

Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.

14hr 12hr 1h 5h 9h 13h 17h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.

View detailed monthly data
MonthDaylight HoursPeak Sun HoursDay Length
January 8.8 hr 3.3 hr Short day
February 10.1 hr 4.1 hr Short day
March 11.6 hr 5.2 hr Short day
April 13.3 hr 6.6 hr Neutral
May 14.8 hr 7.6 hr Long day
June 15.6 hr 8.7 hr Long day
July 15.3 hr 8.8 hr Long day
August 14 hr 7.5 hr Long day
September 12.3 hr 6.1 hr Neutral
October 10.6 hr 5.2 hr Short day
November 9.1 hr 3.4 hr Short day
December 8.4 hr 2.9 hr Short day

Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.

Soil Temperature & Composting Calendar

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Plant Warm Crops When

Soil reaches 60°F+

Soil warm enough from Jun through Sep.

Best Month to Compost

Jul

Microbial activity peaks when soil is warm.

Active Composting

4 months

Short season — insulate pile or use indoor vermicomposting.

60°F 70°F 20° 40° 60° 80° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan 7°F 16°F ❄️ Dormant ~36 weeks
Feb 8°F 17°F ❄️ Dormant ~36 weeks
Mar 19°F 22°F ❄️ Dormant ~36 weeks
Apr 36°F 33°F ❄️ Dormant ~36 weeks
May 49°F 47°F 🐢 Slow ~24 weeks
Jun 61°F 56°F ♻️ Active ~14 weeks
Jul 67°F 62°F 🔥 Peak ~8 weeks
Aug 69°F 65°F 🔥 Peak ~8 weeks
Sep 62°F 59°F ♻️ Active ~14 weeks
Oct 46°F 50°F 🐢 Slow ~24 weeks
Nov 31°F 37°F ❄️ Dormant ~36 weeks
Dec 16°F 27°F ❄️ Dormant ~36 weeks

Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.

Pest & Disease Pressure in Aroostook County

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Insect Pest Pressure

4.4 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

5.2 / 10

Moderate — watch for mildew and blight during wet periods.

Seasonal Risk

Spring Low
Summer Moderate
Fall Low
Winter Low
View 3 common pests in your area
PestRisk LevelPeak Months
Aphids Low Jun, Jul, Aug
Cabbage worms Moderate Jun, Jul, Aug
Slugs Moderate May, Jun, Jul, Aug
Organic pest management tips
  • Use row covers on susceptible crops during peak pest months
  • Apply neem oil preventatively every 7-14 days during active pest season
  • Interplant with strong-scented herbs (basil, marigold) to confuse pests
  • Hand-pick larger pests (beetles, caterpillars) in early morning when they're sluggish
  • Practice crop rotation — never plant the same family in the same spot within 3 years

Cover Crops for Aroostook County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.

Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 21 Jul 30 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 17 Jul 30 ✓ Yes Living mulch, fixes nitrogen, permanent ground cover
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
Crop Plant By Terminate N-Fixing Soil Benefit
Sunflowers Jun 11 Sep 3 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (3 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Oats Aug 12 Apr 27 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jul 1 May 4 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 22 Apr 27 Erosion control, weed suppression, good biomass

Wind & Microclimate

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 14 mph   Summer: 10 mph

Fall: 11 mph   Winter: 17 mph

Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.

Windbreak Benefit

6.8/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Low

Relatively flat terrain (280 ft range). Frost pocket risk is minimal — garden placement is flexible.

Rainwater Harvesting Potential

How much water you can collect, when to collect it, and what size system you need for your garden.

Annual Collection

19,686 gal

Per 1,000 sq ft of roof area (at 80% collection efficiency)

Recommended Setup

6 rain barrels (55 gal each)

For a typical 500 sq ft garden. Serious collectors: consider a 750 gal tank.

Legal Status

Unrestricted

Rainwater harvesting is fully legal in your state with no restrictions.

Best Collection Months

Jun, Jul, Aug, Sep

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

Jan, Feb, Nov

Dry months when you'll rely on stored water — size your storage for this gap.

Rainwater collection tips for your area
  • Your county receives approximately 39.5 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 19,686 gallons annually
  • Rainwater harvesting is fully legal in your state
  • Stock up on stored water before your dry season (Jan, Feb, Nov)
  • Use a first-flush diverter to keep roof debris out of your collection

Soil & Growing Conditions in Aroostook County

Soil Type

Silt Loam

Soil pH 4.9–6.3 · Moderately Well Drained drainage

Good candidate for raised beds to maximise drainage and extend the season.

Watering Needs

Drought stress: 1.5/10

Aroostook County has very low drought pressure. Natural rainfall usually meets garden needs — water only during extended dry spells.

Season Tips

129-day frost-free season

A short season means indoor starts are critical for warm-season crops. Prioritise cold-hardy, fast-maturing varieties and use row covers to extend autumn harvests.

Free Garden Planner

Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.

Get My Free Planner →

Recommended for Your Garden

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🍂
Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Aroostook County

87 vegetables that grow well in Zone 3b with planting dates for Aroostook County.

Show all 87 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash Apr 6 Jun 1 Jun 8 Aug 31 – Oct 5 80–100
Amaranth Mar 16 Jun 1 Jun 8 Sep 7 – Oct 12 90–120
Arugula Apr 6 May 11 May 18 Jun 22 – Aug 24 30–50
Asparagus Jun 1 730–1095
Beets May 11 Jul 6 – Aug 3 50–70
Belgian Endive Apr 6 May 11 May 18 Sep 7 – Sep 21 110–150
Black Beans Jun 1 Aug 31 – Oct 5 90–120
Bok Choy Apr 6 May 11 May 18 Jun 29 – Aug 3 40–60
Broccoli Apr 6 May 11 May 18 Jul 20 – Aug 31 60–90
Broccoli Rabe Apr 6 May 11 May 18 Jun 29 – Aug 3 40–60
Brussels Sprouts Apr 6 May 11 May 18 Aug 17 – Sep 21 90–130
Butternut Squash Apr 6 Jun 1 Jun 8 Sep 7 – Oct 12 85–110
Cabbage Apr 6 May 11 May 18 Jul 20 – Sep 14 60–100
Carrots May 11 Jul 13 – Aug 17 60–80
Cauliflower Apr 6 May 11 May 18 Jul 13 – Sep 14 55–100
Celeriac Apr 6 May 11 May 18 Aug 31 – Sep 21 100–120
Celery Apr 6 May 11 May 18 Aug 10 – Sep 21 80–120
Celtuce Apr 6 May 11 May 18 Jul 20 – Aug 31 60–90
Chard Apr 6 May 11 May 18 Jul 13 – Aug 31 50–60
Chickpeas Apr 6 May 11 May 18 Aug 10 – Sep 21 80–110
Chicory Apr 6 May 11 May 18 Jul 20 – Aug 31 60–85
Chinese Cabbage Apr 6 May 11 May 18 Jul 13 – Aug 10 50–70
Collard Greens Apr 6 May 11 May 18 Jul 13 – Sep 14 55–75
Corn Jun 1 Aug 3 – Sep 28 60–100
Cress Apr 6 May 11 May 18 Jun 1 – Jun 22 14–21
Crookneck Squash Apr 6 Jun 1 Jun 8 Jul 27 – Aug 24 45–60
Cucumber Apr 6 Jun 1 Jun 8 Aug 3 – Sep 28 50–70
Daikon May 11 Jul 6 – Aug 3 50–70
Delicata Squash Apr 6 Jun 1 Jun 8 Aug 31 – Oct 5 80–100
Edamame Jun 1 Aug 17 – Sep 28 75–100
Endive Apr 6 May 11 May 18 Jul 6 – Aug 10 45–65
Escarole Apr 6 May 11 May 18 Jul 13 – Aug 10 50–70
Fava Beans Apr 6 May 11 May 18 Aug 3 – Sep 14 75–100
Garlic 90–240
Green Beans Jun 1 Jul 27 – Sep 21 50–65
Horseradish Jun 1 Oct 5 120–180
Hubbard Squash Apr 6 Jun 1 Jun 8 Sep 21 – Oct 12 100–120
Kabocha Apr 6 Jun 1 Jun 8 Sep 7 – Oct 5 85–100
Kai Lan Apr 6 May 11 May 18 Jul 6 – Aug 3 45–60
Kale Apr 6 May 11 May 18 Jul 13 – Sep 7 50–70
Kidney Beans Jun 1 Aug 31 – Oct 5 85–110
Kohlrabi Apr 6 May 11 May 18 Jul 6 – Aug 10 45–65
Komatsuna Apr 6 May 11 May 18 Jun 22 – Jul 27 35–50
Leeks Apr 6 May 11 May 18 Aug 17 – Sep 21 90–150
Lentils Apr 6 May 11 May 18 Aug 10 – Sep 21 80–110
Lettuce Apr 6 May 11 May 18 Jun 22 – Aug 31 30–60
Lima Beans Jun 1 Aug 3 – Sep 14 60–90
Mache Apr 6 May 11 May 18 Jun 29 – Aug 3 40–60
Microgreens Apr 6 May 11 May 18 May 25 – Jun 22 7–21
Mizuna Apr 6 May 11 May 18 Jun 22 – Jul 20 30–45
Mustard Greens Apr 6 May 11 May 18 Jun 22 – Aug 24 30–50
Napa Cabbage Apr 6 May 11 May 18 Jul 13 – Aug 17 55–75
Onion Apr 6 May 11 May 18 Aug 17 – Sep 21 90–120
Pac Choi Apr 6 May 11 May 18 Jun 29 – Jul 27 40–55
Parsnip May 11 Aug 24 – Sep 14 100–130
Patty Pan Squash Apr 6 Jun 1 Jun 8 Jul 27 – Aug 24 45–60
Peas Apr 6 May 11 May 18 Jul 13 – Sep 7 55–70
Peppers Mar 2 Jun 1 Jun 8 Aug 10 – Oct 12 60–90
Pole Beans Mar 16 Jun 1 Jun 8 Aug 3 – Sep 28 55–70
Potatoes Mar 16 Jun 1 Jun 8 Aug 17 – Oct 12 70–120
Pumpkin Apr 6 Jun 1 Jun 8 Sep 7 – Oct 12 85–120
Purslane Apr 6 May 11 May 18 Jun 29 – Aug 3 40–60
Radish May 11 Jun 8 – Jun 29 22–35
Rhubarb Jun 15 365–730
Romanesco Apr 6 May 11 May 18 Aug 3 – Sep 14 75–100
Rutabaga May 11 Aug 3 – Sep 7 80–100
Salsify May 11 Aug 24 – Sep 14 100–130
Savoy Cabbage Apr 6 May 11 May 18 Jul 27 – Sep 21 70–110
Scallions Apr 6 May 11 May 18 Jul 13 – Aug 10 50–70
Scarlet Runner Beans Mar 16 Jun 1 Jun 8 Aug 10 – Sep 14 60–80
Shiso Mar 23 May 25 Jun 8 Aug 3 – Sep 28 50–70
Snap Peas Mar 16 Jun 1 Jun 8 Aug 3 – Sep 28 55–70
Snow Peas Apr 6 May 11 May 18 Jul 13 – Sep 7 50–65
Soybeans Jun 1 Aug 24 – Oct 5 80–120
Spaghetti Squash Apr 6 Jun 1 Jun 8 Sep 7 – Oct 5 85–100
Spinach Apr 6 May 11 May 18 Jun 22 – Aug 24 35–50
Squash (Summer) Apr 6 Jun 1 Jun 8 Jul 27 – Sep 28 45–65
Squash (Winter) Apr 6 Jun 1 Jun 8 Aug 31 – Oct 12 80–120
Sunchoke Jun 1 Sep 21 – Oct 5 110–150
Sunflower Mar 16 Jun 1 Jun 8 Aug 17 – Oct 5 70–100
Sweet Corn Jun 1 Aug 3 – Sep 14 60–90
Tatsoi Apr 6 May 11 May 18 Jun 22 – Jul 27 35–50
Tomatoes Mar 16 Jun 1 Jun 8 Aug 10 – Oct 12 60–85
Turnip May 11 Jun 22 – Jul 27 40–60
Watercress Apr 6 May 11 May 18 Jun 29 – Aug 3 40–60
Wax Beans Jun 1 Jul 27 – Sep 21 50–65
Zucchini Apr 6 Jun 1 Jun 8 Jul 27 – Sep 21 45–60

🍓 Fruits to Grow in Aroostook County

15 fruits that grow well in Zone 3b with planting dates for Aroostook County.

Show all 15 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Jun 15 Sep 14 – Oct 19 90–180
Aronia Jun 15 730–1095
Blueberries Jun 15 730–1095
Cranberries Jun 15 730–1095
Currants Jun 15 730–1095
Elderberries Jun 15 730–1095
Goji Berries Jun 15 730–1095
Gooseberries Jun 15 730–1095
Hardy Kiwi Jun 15 1095–1825
Haskaps Jun 15 730–1095
Jostaberry Jun 15 730–1095
Lingonberries Jun 15 730–1095
Raspberries Jun 15 365–730
Serviceberries Jun 15 730–1095
Strawberries Jun 15 Sep 14 – Oct 19 90–365

🌿 Herbs to Grow in Aroostook County

22 herbs that grow well in Zone 3b with planting dates for Aroostook County.

Show all 22 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica Apr 6 May 11 May 11 365–730
Bee Balm May 25 Aug 24 – Sep 28 90–120
Borage Apr 6 May 11 May 11 Jul 6 – Aug 24 50–60
Caraway Apr 6 May 11 May 11 365–450
Catnip May 25 Jul 27 – Sep 28 60–80
Chamomile Apr 6 May 11 May 11 Jul 13 – Sep 14 60–90
Chervil Apr 6 May 11 May 11 Jun 22 – Aug 24 40–60
Chives May 25 Jul 27 – Sep 28 60–90
Cilantro Apr 6 May 11 May 11 Jun 22 – Aug 24 40–60
Comfrey May 25 Jul 27 – Sep 28 60–90
Dill Apr 6 May 11 May 11 Jun 22 – Aug 24 40–60
Echinacea May 25 Sep 28 120–180
Garlic Chives May 25 Jul 27 – Sep 28 60–90
Horehound May 25 Aug 10 – Sep 28 75–90
Hyssop May 25 Aug 3 – Sep 28 70–90
Lemon Balm May 25 Jul 27 – Sep 14 60–70
Lovage May 25 Aug 3 – Sep 28 70–90
Mint May 25 Jul 27 – Sep 28 60–90
Parsley Apr 6 May 11 May 11 Jul 13 – Sep 14 60–80
Sorrel Apr 6 May 11 May 11 Jun 22 – Aug 24 40–60
Valerian May 25 Sep 28 120–180
Yarrow May 25 Aug 24 – Sep 28 90–120

Monthly Planting Guide for Aroostook County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Aroostook County.

Frequently Asked Questions

What planting zone is Aroostook County, ME?

Aroostook County is in USDA Hardiness Zone 3b. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.

When is the last frost in Aroostook County, ME?

Based on 31 years of NOAA weather station data, the median last spring frost in Aroostook County falls around May 18. In 8 out of 10 years, last frost lands between May 6 and June 1 — a 26-day window of variability. Use June 1 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Aroostook County, ME?

The median first fall frost in Aroostook County arrives around September 24. In cold years it can arrive as early as September 14; in mild years as late as October 5. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Aroostook County?

Aroostook County has a frost-free growing season of approximately 129 days. Focus on short-season varieties and start warm-season crops indoors 6–8 weeks before last frost.

What is the soil like in Aroostook County for gardening?

Aroostook County has predominantly Silt Loam soil with a pH range of 4.9–6.3 and Moderately Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Aroostook County?

Aroostook County has commercial agriculture that includes Hay, Dairy, Corn, Sweet Corn. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Aroostook County a good location for home gardening?

Aroostook County scores 79/100 (Good) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. This is an above-average location for home gardening with relatively predictable growing conditions.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — 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.

Level Up Your Garden

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 2 weather stations in or near Aroostook County (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: April 2026.