When to Plant Arugula in Aroostook County, ME
May in Aroostook County, Maine — your action list
We've pulled the most time-sensitive tasks for Aroostook County, Maine this May and put them front and centre. Tackle them in order.
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Plant out arugula
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Put arugula seeds straight in the ground
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
June prep starts now
- Starting indoors: arugula
- First harvests: arugula
Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.
Aroostook County, Maine is in USDA Zone 4a. 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 78°F, so choose short-season varieties of Arugula to ensure they mature before fall.
Aroostook County Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.3
Drainage
Well Drained
Plant 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 Aroostook County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (4.9–6.3) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Aroostook County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.8%). Annual compost additions will help Arugula.
How to Plant Arugula
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Arugula
Sow every 3.4 weeks. Last sowing by Aug 05 to harvest before frost.
For a dedicated fall crop, sow by Jul 02.
Plant Water Budget
Monthly Watering Guide for Arugula
Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Arugula Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.8" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.3" | 0" | ❄️ Dormant |
| Apr | — | 3.5" | 0" | ❄️ Dormant |
| May | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Oct | — | 3.2" | 0" | ❄️ Dormant |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Aroostook County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Arugula 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.
Arugula Planting Timeline — Aroostook County, ME
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | June 22 | Jun 22 – Aug 24 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 4a
📆 Growing Season
129 days in Aroostook County
Growing Tips for Arugula in Aroostook County
Direct sow Arugula outdoors after May 18 in Aroostook County when soil has warmed and frost danger has passed.
Your generous 129.0-day season in Aroostook County allows multiple plantings of Arugula. Sow every 15.0 days for continuous harvest.
Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
Frequently Asked Questions
When should I plant Arugula in Aroostook County, ME?
Aroostook County is in Zone 4a with an average last frost of May 18. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Aroostook County, ME?
Aroostook County, Maine is in USDA Hardiness Zone 4a. The average last spring frost is May 18 and first fall frost is September 24.
Your Aroostook County Garden Planner — Free
A 24-page printable planner built for Aroostook County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.