When to Plant Mitsuba in St. Lawrence County, NY
May in St. Lawrence County, New York — your action list
Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.
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Get mitsuba in the ground
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Direct-sow mitsuba
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
Coming up in June — start thinking about
- 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.
St. Lawrence County, New York is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 2, giving you a growing season of approximately 145 days.
At an elevation of 688 feet, St. Lawrence County receives approximately 39.2 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.
St. Lawrence County Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.6
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 St. Lawrence County
How your county's soil matches Mitsuba's growing requirements.
Soil pH
Your soil pH (4.9–6.6) is more acidic than Mitsuba prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in St. Lawrence County is excellent for Mitsuba — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Mitsuba.
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 24 to harvest before frost.
For a dedicated fall crop, sow by Jul 10.
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 | — | 2.7" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | — | 3.1" | 0" | ❄️ Dormant |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 3.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in St. Lawrence 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 — St. Lawrence County, NY
Mitsuba Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | May 3 | May 3 – May 24 |
| Harvest | June 28 | Jun 28 – Aug 23 |
| Fall Sowing | July 10 | Jul 10 – Jul 24 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| 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
1"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 4b
📆 Growing Season
145 days in St. Lawrence County
Growing Tips for Mitsuba in St. Lawrence County
Direct sow Mitsuba outdoors after May 10 in St. Lawrence 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 St. Lawrence County, NY?
St. Lawrence County is in Zone 4b with an average last frost of May 10. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Lawrence County, NY?
St. Lawrence County, New York is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 2.
Your St. Lawrence County Garden Planner — Free
A 24-page printable planner built for St. Lawrence County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.