When to Plant Mitsuba in Grant County, OR
Your May planting checklist for Grant County, Oregon
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Move mitsuba into the garden
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Direct-sow mitsuba
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
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.
Grant County, Oregon is in USDA Zone 6b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.
At an elevation of 2,838 feet, Grant County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mitsuba to ensure they mature before fall.
Grant County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.4
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 Grant County
How your county's soil matches Mitsuba's growing requirements.
Soil pH
Your soil pH (5.4–6.4) is more acidic than Mitsuba prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Grant 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 (4.8%) — Mitsuba will thrive.
How to Plant Mitsuba
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mitsuba
Sow every 5.7 weeks. Last sowing by Jul 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 02.
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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 2.9" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | — | 1.3" | 0" | ❄️ Dormant |
| Jun | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jul | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Aug | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Sep | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Oct | — | 1.8" | 0" | ❄️ Dormant |
| Nov | — | 3.1" | 0" | ❄️ Dormant |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Grant 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 — Grant County, OR
Mitsuba Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 2 | May 2 – May 16 |
| Transplant Outdoors | May 30 | May 30 – Jun 13 |
| Direct Sow | May 23 | May 23 – Jun 13 |
| Harvest | July 25 | Jul 25 – Sep 19 |
| Fall Sowing | July 2 | Jul 2 – Jul 16 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6b
📆 Growing Season
96 days in Grant County
Growing Tips for Mitsuba in Grant County
Direct sow Mitsuba outdoors after June 06 in Grant 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.
Grant County receives only 23" of rain annually. Mitsuba needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Grant County, OR?
Grant County is in Zone 6b with an average last frost of June 6. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grant County, OR?
Grant County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 6 and first fall frost is September 10.
Your Grant County Garden Planner — Free
A 24-page printable planner built for Grant County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.