When to plant Mitsuba in Williamson County, IL
In Williamson County, plant Mitsuba in spring between March 27 and April 17, once soil temps hold above 50°F. Williamson County's last frost averages April 10, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between August 11 and August 25 — roughly 50–70 days before the first frost on October 20.
When to Plant Mitsuba in Williamson County, IL
Williamson County, Illinois gardeners: here's your June plan
June is a pivotal month for Williamson County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Basket week: mitsuba
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Looking ahead to July
- 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.
Williamson County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 20, giving you a growing season of approximately 193 days.
At an elevation of 1,253 feet, Williamson County receives approximately 38.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Mitsuba during the growing season.
Williamson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Mitsuba 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 Williamson County
How your county's soil matches Mitsuba's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Mitsuba's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Williamson County is excellent for Mitsuba — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — 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 Aug 11 to harvest before frost.
For a dedicated fall crop, sow by Aug 11.
Mitsuba Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Williamson 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 — Williamson County, IL
Mitsuba Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Harvest | May 29 | May 29 – Jul 24 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| 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: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
193 days in Williamson County
Growing Tips for Mitsuba in Williamson County
Direct sow Mitsuba outdoors after April 10 in Williamson 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 Williamson County, IL?
Williamson County is in Zone 7a with an average last frost of April 10. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamson County, IL?
Williamson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 20.
When should I plant Mitsuba in Williamson County, IL?
In Williamson County, IL, plant Mitsuba after the last frost (around April 10) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Williamson County, IL for Mitsuba?
Williamson County sits in USDA Zone 7a. Mitsuba grows reliably in zones 4a through 9b, so it's a good fit here.
Can Mitsuba grow in Williamson County's climate?
Yes — Mitsuba grows well in Williamson County's temperate climate. Williamson County averages a 193-day frost-free season, with last frost around April 10 and first frost around October 20.
Your Williamson County Garden Planner — Free
A 22-page printable planner built for Williamson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.