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When to Plant Mizuna in Tillman County, OK

Tillman County, Oklahoma Zone 8a May

Your May gardening checklist

Each item below is timed to Tillman County, Oklahoma's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 3
Avg. first frost November 6
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Get mizuna seeds going inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Harvest mizuna as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June will be here before you know it — start on
  • First harvests: mizuna

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Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.

Tillman County, Oklahoma is in USDA Zone 8a. The average last spring frost is April 3 and the first fall frost is November 6, giving you a growing season of approximately 217 days.

At an elevation of 807 feet, Tillman County receives approximately 25.1 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Mizuna during the growing season.

Tillman County, OK (Zone 8a) Long season
217 days
Last Spring Frost April 3
217 growing days
First Fall Frost November 6
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Tillman County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (159 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Apr 25 – May 23
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 8 – Jun 5
Safe Start (90%) ✓ Fits season (159 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 20 – Jun 17

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 Tillman County

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

Soil pH

Your soil pH (6.2–7.5) is within Mizuna's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Mizuna.

How to Plant Mizuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Mizuna

8
successive plantings in your 217-day season

Sow every 3.4 weeks. Last sowing by Sep 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 993 gal / 100 sq ft

Monthly Watering Guide for Mizuna

Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mizuna Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 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 (Apr–Nov in Tillman County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mizuna 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.

Mizuna needs ~600 GDD — county provides 3,472 GDD Excellent fit

Mizuna Planting Timeline — Tillman County, OK

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest May 8 May 8 – Jun 5
Fall Sowing August 28 Aug 28 – Sep 11

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

217 days in Tillman County

Growing Tips for Mizuna in Tillman County

Direct sow Mizuna outdoors after April 03 in Tillman County when soil has warmed and frost danger has passed.

Your generous 217.0-day season in Tillman County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.

Common pests for Mizuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Tillman County, OK?

Tillman County is in Zone 8a with an average last frost of April 3. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tillman County, OK?

Tillman County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is April 3 and first fall frost is November 6.

🌱

Your Tillman County Garden Planner — Free

A 24-page printable planner built for Tillman 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.

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

Sources & credits

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