When to Plant Chard in St. Johns 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.
St. Johns County, Florida is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.
At an elevation of 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Chard may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.
St. Johns County Soil Profile
Soil Type
Sand
Soil pH
4.9-6.1
Drainage
Well Drained
Plant Planting Risk Windows
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 St. Johns County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (4.9–6.1) is more acidic than Chard prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. Johns 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 (1.5%). Add 2-3 inches of compost before planting Chard.
How to Plant Chard
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Chard
Sow every 5.7 weeks. Last sowing by Oct 03 to harvest before frost.
For a dedicated fall crop, sow by Oct 07.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 2.4" | 0" | ❄️ Dormant |
| Feb | 3.5" | 2.4" | 1.1" | 💧 Light watering |
| Mar | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Apr | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| May | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 7" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 7.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 6.9" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | 3.5" | 2.1" | 1.4" | 💧 Light watering |
| Dec | 3.5" | 2.3" | 1.2" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. Johns County). Supplement amounts are based on average rainfall — 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" — 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.
Chard Planting Timeline — St. Johns County, FL
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 12 | Jan 12 – Jan 26 |
| Transplant Outdoors | February 9 | Feb 9 – Feb 23 |
| Direct Sow | January 19 | Jan 19 – Feb 9 |
| Harvest | April 6 | Apr 6 – May 25 |
| Fall Sowing | October 7 | Oct 7 – Oct 21 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
296 days in St. Johns County
Growing Tips for Chard in St. Johns County
Direct sow Chard outdoors after February 09 in St. Johns County when soil has warmed and frost danger has passed.
Sandy soil in St. Johns County dries quickly — mulch Chard with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Summer highs in St. Johns County reach 99°F — 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
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Chard in Other Locations
Frequently Asked Questions
When should I plant Chard in St. Johns County, FL?
St. Johns County is in Zone 9a with an average last frost of February 9. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Johns County, FL?
St. Johns County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 2.
Plan Your Garden with Confidence
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