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When to Plant Mizuna in Smith County, TX

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.

Smith County, Texas is in USDA Zone 8a. The average last spring frost is March 9 and the first fall frost is November 16, giving you a growing season of approximately 252 days.

At an elevation of 179 feet, Smith County receives approximately 59.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Mizuna may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Mizuna will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mizuna root diseases.

Smith County, TX (Zone 8a) Long season
252 days
Last Spring Frost March 9
252 growing days
First Fall Frost November 16

Smith County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (194 days to spare)
Start indoors: Jan 24 Transplant: Feb 28 🍅 Harvest: Apr 4 – May 2
Recommended (50%) ✓ Fits season (189 days to spare)
Start indoors: Feb 2 Transplant: Mar 9 🍅 Harvest: Apr 13 – May 11
Safe Start (90%) ✓ Fits season (184 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 3 – May 31

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 Smith County

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

Soil pH

Your soil pH (5.6โ€“6.5) overlaps with Mizuna's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

Sandy soil in Smith County warms quickly in spring but drains fast. Mizuna will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.1%). 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

10
successive plantings in your 252-day season

Sow every 3.4 weeks. Last sowing by Oct 02 to harvest before frost.

For a dedicated fall crop, sow by Sep 07.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 19 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 6.5" 0" โœ… Rainfall sufficient
May 4.3" 8.1" 0" โœ… Rainfall sufficient
Jun 4.3" 8.7" 0" โœ… Rainfall sufficient
Jul 4.3" 8.1" 0" โœ… Rainfall sufficient
Aug 4.3" 6.8" 0" โœ… Rainfall sufficient
Sep 4.3" 6.2" 0" โœ… Rainfall sufficient
Oct 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Smith County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~825 GDD — county provides 5,544 GDD Excellent fit

Mizuna Planting Timeline โ€” Smith County, TX

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 โ€“ Feb 16
Transplant Outdoors March 9 Mar 9 โ€“ Mar 23
Direct Sow February 23 Feb 23 โ€“ Mar 16
Harvest April 13 Apr 13 โ€“ May 11
Fall Sowing September 7 Sep 7 โ€“ Sep 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

30โ€“45 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

252 days in Smith County

Growing Tips for Mizuna in Smith County

Direct sow Mizuna outdoors after March 09 in Smith County when soil has warmed and frost danger has passed.

Sandy soil in Smith County dries quickly โ€” mulch Mizuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96ยฐF in Smith County, provide afternoon shade for Mizuna and water deeply in the morning.

Your generous 252.0-day season in Smith 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 Smith County, TX?

Smith County is in Zone 8a with an average last frost of March 9. Plan your Mizuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Smith County, TX?

Smith County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 9 and first fall frost is November 16.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 Smith County, TX. Local conditions may vary. Last updated: April 2026.