When to Plant Arugula in Clearwater County, MN
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.
Clearwater County, Minnesota is in USDA Zone 3b. The average last spring frost is May 15 and the first fall frost is September 28, giving you a growing season of approximately 136 days.
At an elevation of 1,074 feet, Clearwater County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Arugula to ensure they mature before fall.
Clearwater County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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 Clearwater County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Arugula's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Clearwater County is excellent for Arugula — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Arugula.
Organic Matter
Organic matter is excellent (4.6%) — Arugula will thrive.
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 09 to harvest before frost.
For a dedicated fall crop, sow by Jul 06.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.8" | 0" | ❄️ Dormant |
| May | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | — | 2.5" | 0" | ❄️ Dormant |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Clearwater 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 — Clearwater County, MN
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 8 | May 8 – May 29 |
| Harvest | June 19 | Jun 19 – Aug 21 |
| Fall Sowing | July 6 | Jul 6 – Jul 20 |
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 | 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: acceptable
🗺️ USDA Zone
Zone 3b
📆 Growing Season
136 days in Clearwater County
Growing Tips for Arugula in Clearwater County
Direct sow Arugula outdoors after May 15 in Clearwater County when soil has warmed and frost danger has passed.
Your generous 136.0-day season in Clearwater 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
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Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
Frequently Asked Questions
When should I plant Arugula in Clearwater County, MN?
Clearwater County is in Zone 3b with an average last frost of May 15. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clearwater County, MN?
Clearwater County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 15 and first fall frost is September 28.
Plan Your Garden with Confidence
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