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When to Plant Mustard Greens in Duval County, FL

Duval County, Florida Zone 9b May

Top priorities for Duval County, Florida gardeners in May

May is a pivotal month for Duval County, Florida gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 24
Avg. first frost November 29
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting mustard greens

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of June
  • 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.

Duval County, Florida is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is November 29, giving you a growing season of approximately 278 days.

At an elevation of 337 feet, Duval County receives approximately 56.9 inches of rainfall annually with predominantly sand soil. Summer highs average 102°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.

Duval County, FL (Zone 9b) Year-round
278 days
Last Spring Frost February 24
278 growing days
First Fall Frost November 29

Duval County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (185 days to spare)
Start indoors: Jan 14 Transplant: Feb 11 🍅 Harvest: Mar 18 – May 20
Recommended (50%) ✓ Fits season (180 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Mar 31 – Jun 2
Safe Start (90%) ✓ Fits season (176 days to spare)
Start indoors: Feb 21 Transplant: Mar 21 🍅 Harvest: Apr 25 – Jun 27

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 Duval County

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

Soil pH

Your soil pH (5.0–5.8) is more acidic than Mustard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.4%). 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

11
successive plantings in your 278-day season

Sow every 3.4 weeks. Last sowing by Oct 10 to harvest before frost.

For a dedicated fall crop, sow by Oct 04.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.6" 0" ❄️ Dormant
Feb 3" 2.8" 0.2" 💧 Light watering
Mar 3" 3.6" 0" ✅ Rainfall sufficient
Apr 3" 3" 0" ✅ Rainfall sufficient
May 3" 3.5" 0" ✅ Rainfall sufficient
Jun 3" 8.7" 0" ✅ Rainfall sufficient
Jul 3" 7.8" 0" ✅ Rainfall sufficient
Aug 3" 8.9" 0" ✅ Rainfall sufficient
Sep 3" 6.3" 0" ✅ Rainfall sufficient
Oct 3" 4.7" 0" ✅ Rainfall sufficient
Nov 3" 2.6" 0.4" 💧 Light watering
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Duval 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 ~1,060 GDD — county provides 7,393 GDD Excellent fit

Mustard Greens Planting Timeline — Duval County, FL

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors February 24 Feb 24 – Mar 10
Direct Sow February 3 Feb 3 – Feb 24
Harvest March 31 Mar 31 – Jun 2
Fall Sowing October 4 Oct 4 – Oct 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

278 days in Duval County

Growing Tips for Mustard Greens in Duval County

Direct sow Mustard Greens outdoors after February 24 in Duval County when soil has warmed and frost danger has passed.

Sandy soil in Duval 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 102°F in Duval County, provide afternoon shade for Mustard Greens and water deeply in the morning.

Your generous 279.0-day season in Duval 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 Duval County, FL?

Duval County is in Zone 9b with an average last frost of February 24. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Duval County, FL?

Duval County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is November 29.

🌱

Your Duval County Garden Planner — Free

A 24-page printable planner built for Duval County (Zone 9b). 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 Duval 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.