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When to Plant Chard in Duval County, FL

Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

Duval County, Florida is in USDA Zone 9a. 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 102ยฐF, so Chard may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Chard will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Chard root diseases.

Duval County, FL (Zone 9a) 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 (178 days to spare)
Start indoors: Jan 14 Transplant: Feb 11 🍅 Harvest: Apr 8 – May 27
Recommended (50%) ✓ Fits season (173 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Apr 21 – Jun 9
Safe Start (90%) ✓ Fits season (169 days to spare)
Start indoors: Feb 21 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 4

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 Chard's growing requirements.

Soil pH

Your soil pH (5.0โ€“5.8) is more acidic than Chard prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Duval County warms quickly in spring but drains fast. Chard 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 Chard.

How to Plant Chard

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Chard

6
successive plantings in your 278-day season

Sow every 5.7 weeks. Last sowing by Sep 30 to harvest before frost.

For a dedicated fall crop, sow by Oct 04.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Chard

Chard needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Chard Needs Rainfall You Supplement Action
Jan โ€” 2.6" 0" โ„๏ธ Dormant
Feb 3.5" 2.8" 0.7" ๐Ÿ’ง Light watering
Mar 3.5" 3.6" 0" โœ… Rainfall sufficient
Apr 3.5" 3" 0.5" ๐Ÿ’ง Light watering
May 3.5" 3.5" 0" โœ… Rainfall sufficient
Jun 3.5" 8.7" 0" โœ… Rainfall sufficient
Jul 3.5" 7.8" 0" โœ… Rainfall sufficient
Aug 3.5" 8.9" 0" โœ… Rainfall sufficient
Sep 3.5" 6.3" 0" โœ… Rainfall sufficient
Oct 3.5" 4.7" 0" โœ… Rainfall sufficient
Nov 3.5" 2.6" 0.9" ๐Ÿ’ง Light watering
Dec โ€” 2.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Duval County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Chard 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.

Chard needs ~1,458 GDD — county provides 7,393 GDD Excellent fit

Chard Planting Timeline โ€” Duval County, FL

Chard Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 โ€“ Feb 10
Transplant Outdoors February 24 Feb 24 โ€“ Mar 10
Direct Sow February 3 Feb 3 โ€“ Feb 24
Harvest April 21 Apr 21 โ€“ Jun 9
Fall Sowing October 4 Oct 4 โ€“ Oct 18

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

278 days in Duval County

Growing Tips for Chard in Duval County

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

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

Summer highs in Duval County reach 102ยฐF โ€” grow Chard as a spring or fall crop. Use shade cloth if planting in summer.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Duval County, FL?

Duval County is in Zone 9a with an average last frost of February 24. Plan your Chard planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Duval County, FL?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Duval County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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: April 2026.