When to Plant Chard in Martin 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.
Martin County, Florida is in USDA Zone 10a. The average last spring frost is January 25 and the first fall frost is December 13, giving you a growing season of approximately 322 days.
At an elevation of 80 feet, Martin County receives approximately 56.3 inches of rainfall annually with predominantly sand soil. Summer highs average 88°F, providing good warmth for Chard during the growing season. 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.
Martin County Soil Profile
Soil Type
Sand
Soil pH
5.1-5.7
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 Martin County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (5.1–5.7) is more acidic than Chard prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Martin County warms quickly in spring but drains fast. Chard will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Chard.
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 14 to harvest before frost.
For a dedicated fall crop, sow by Oct 18.
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 | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Feb | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Mar | 3.5" | 3" | 0.5" | 💧 Light watering |
| Apr | 3.5" | 2.3" | 1.2" | 💧 Light watering |
| May | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Jun | 3.5" | 8.6" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 7.9" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 8.4" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 8.2" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Nov | 3.5" | 2.2" | 1.3" | 💧 Light watering |
| Dec | 3.5" | 2.1" | 1.4" | 💧 Light watering |
Water needs are for active growing months only (Jan–Dec in Martin 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 — Martin County, FL
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 28 | Dec 28 – Jan 11 |
| Transplant Outdoors | January 25 | Jan 25 – Feb 8 |
| Direct Sow | January 4 | Jan 4 – Jan 25 |
| Harvest | March 22 | Mar 22 – May 10 |
| Fall Sowing | October 18 | Oct 18 – Nov 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Transplant Outdoors |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | Fall Sowing |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.8"/week · 1-2 times/week
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 10a
📆 Growing Season
322 days in Martin County
Growing Tips for Chard in Martin County
Direct sow Chard outdoors after January 25 in Martin County when soil has warmed and frost danger has passed.
Sandy soil in Martin County dries quickly — mulch Chard with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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
Check more plant combinations with our Companion Planting Checker →
Chard in Other Locations
Frequently Asked Questions
When should I plant Chard in Martin County, FL?
Martin County is in Zone 10a with an average last frost of January 25. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is Martin County, FL?
Martin County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 25 and first fall frost is December 13.
Plan Your Garden with Confidence
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