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When to Plant Mustard Greens in Washington County, FL

Washington County, Florida Zone 9a May

This month in Washington County, Florida

We've pulled the most time-sensitive tasks for Washington County, Florida this May and put them front and centre. Tackle them in order.

Avg. last frost March 5
Avg. first frost November 20
Soil temp (4") 75°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Harvest mustard greens as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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

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Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Washington County, Florida is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 20, giving you a growing season of approximately 260 days.

At an elevation of 196 feet, Washington County receives approximately 50.6 inches of rainfall annually with predominantly sand soil. Summer highs average 97°F, so Mustard Greens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Mustard Greens will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mustard Greens root diseases.

Washington County, FL (Zone 9a) Long season
260 days
Last Spring Frost March 5
260 growing days
First Fall Frost November 20

Washington County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (164 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Mar 30 – Jun 1
Recommended (50%) ✓ Fits season (162 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 9 – Jun 11
Safe Start (90%) ✓ Fits season (162 days to spare)
Start indoors: Feb 27 Transplant: Mar 27 🍅 Harvest: May 1 – Jul 3

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 Washington County

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (4.8–5.9) is more acidic than Mustard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Mustard Greens.

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting Mustard Greens.

How to Plant Mustard Greens

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Mustard Greens

10
successive plantings in your 260-day season

Sow every 3.4 weeks. Last sowing by Oct 01 to harvest before frost.

For a dedicated fall crop, sow by Sep 25.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 214 gal / 100 sq ft

Monthly Watering Guide for Mustard Greens

Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mustard Greens Needs Rainfall You Supplement Action
Jan 2" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3" 2.5" 0.5" 💧 Light watering
Apr 3" 2.2" 0.8" 💧 Light watering
May 3" 3.7" 0" ✅ Rainfall sufficient
Jun 3" 6.8" 0" ✅ Rainfall sufficient
Jul 3" 8.5" 0" ✅ Rainfall sufficient
Aug 3" 6.5" 0" ✅ Rainfall sufficient
Sep 3" 7.3" 0" ✅ Rainfall sufficient
Oct 3" 4" 0" ✅ Rainfall sufficient
Nov 3" 2.1" 0.9" 💧 Light watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Washington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mustard Greens 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.

Mustard Greens needs ~910 GDD — county provides 5,915 GDD Excellent fit

Mustard Greens Planting Timeline — Washington County, FL

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow February 12 Feb 12 – Mar 5
Harvest April 9 Apr 9 – Jun 11
Fall Sowing September 25 Sep 25 – Oct 9

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

260 days in Washington County

Growing Tips for Mustard Greens in Washington County

Direct sow Mustard Greens outdoors after March 05 in Washington County when soil has warmed and frost danger has passed.

Sandy soil in Washington County dries quickly — mulch Mustard Greens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in Washington County, provide afternoon shade for Mustard Greens and water deeply in the morning.

Your generous 260.0-day season in Washington County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.

Common pests for Mustard Greens 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 early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Washington County, FL?

Washington County is in Zone 9a with an average last frost of March 5. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, FL?

Washington County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 20.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington County (Zone 9a). 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 Washington County, FL. 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.