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When to Plant Mitsuba in Jefferson County, OK

Jefferson County, Oklahoma Zone 8a June

What to do in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jefferson County, Oklahoma.

Avg. last frost March 26
Avg. first frost November 9
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Collect mitsuba at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Before July arrives, get these ready
  • First harvests: mitsuba

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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.

Jefferson County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.

At an elevation of 883 feet, Jefferson County receives approximately 24.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Mitsuba during the growing season.

Jefferson County, OK (Zone 8a) Long season
228 days
Last Spring Frost March 26
228 growing days
First Fall Frost November 9

Jefferson County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Mitsuba Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: May 4 – Jun 29
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Feb 19 Transplant: Mar 19 🍅 Harvest: May 14 – Jul 9
Safe Start (90%) ✓ Fits season (118 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 29

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 Jefferson County

How your county's soil matches Mitsuba's growing requirements.

Soil pH

Your soil pH (6.6–7.5) is more alkaline than Mitsuba prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Jefferson County is excellent for Mitsuba — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) — Mitsuba will thrive.

How to Plant Mitsuba

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mitsuba

5
successive plantings in your 228-day season

Sow every 5.7 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 31.

Mitsuba Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,106 gal / 100 sq ft

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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 4.3" 1.7" 2.6" 🚿 Regular watering
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.6" 2.7" 🚿 Regular watering
Nov 4.3" 0.8" 3.5" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Jefferson 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 needs ~1,095 GDD — county provides 4,161 GDD Excellent fit

Mitsuba Planting Timeline — Jefferson County, OK

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors March 19 Mar 19 – Apr 2
Direct Sow March 12 Mar 12 – Apr 2
Harvest May 14 May 14 – Jul 9
Fall Sowing August 31 Aug 31 – Sep 14

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
September Fall Sowing
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_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

228 days in Jefferson County

Growing Tips for Mitsuba in Jefferson County

Direct sow Mitsuba outdoors after March 26 in Jefferson 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.

Jefferson County receives only 25" 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 →

Frequently Asked Questions

When should I plant Mitsuba in Jefferson County, OK?

Jefferson County is in Zone 8a with an average last frost of March 26. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, OK?

Jefferson County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 9.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson County, OK. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.