When to Plant Mitsuba in Benton County, MN
What to do in May
A quick May briefing for Benton County, Minnesota gardeners — what's urgent, what's next, and what can wait.
June prep starts now
- Starting indoors: mitsuba
- First harvests: mitsuba
Mitsuba (Japanese parsley) is a shade-loving herb with trefoil leaves and a mild celery-parsley flavor. It is essential in Japanese cuisine for soups, salads, and garnishes.
Benton County, Minnesota is in USDA Zone 4a. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.
At an elevation of 1,178 feet, Benton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Mitsuba to ensure they mature before fall.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
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 Benton County
How your county's soil matches Mitsuba's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Mitsuba's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Benton County is excellent for Mitsuba — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Mitsuba.
Organic Matter
Organic matter is excellent (4.9%) — Mitsuba will thrive.
How to Plant Mitsuba
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Mitsuba
Sow every 5.7 weeks. Last sowing by Jul 28 to harvest before frost.
For a dedicated fall crop, sow by Jul 14.
Plant Water Budget
Monthly Watering Guide for Mitsuba
Mitsuba needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mitsuba Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | — | 3.4" | 0" | ❄️ Dormant |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Benton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mitsuba 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.
Mitsuba Planting Timeline — Benton County, MN
Mitsuba Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | April 25 | Apr 25 – May 9 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | June 20 | Jun 20 – Aug 15 |
| Fall Sowing | July 14 | Jul 14 – Jul 28 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| 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
1"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 4a
📆 Growing Season
157 days in Benton County
Growing Tips for Mitsuba in Benton County
Direct sow Mitsuba outdoors after May 02 in Benton County when soil has warmed and frost danger has passed.
Common pests for Mitsuba in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow or start indoors in partial shade. Mitsuba prefers cool, moist conditions. Harvest outer stems as needed. Self-sows readily in shaded garden areas.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Mitsuba in Other Locations
Frequently Asked Questions
When should I plant Mitsuba in Benton County, MN?
Benton County is in Zone 4a with an average last frost of May 2. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.
What planting zone is Benton County, MN?
Benton County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 2 and first fall frost is October 6.
Your Benton County Garden Planner — Free
A 24-page printable planner built for Benton 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.