When to Plant Kohlrabi in Putnam County, FL
Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.
Putnam 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 278 feet, Putnam County receives approximately 57.5 inches of rainfall annually with predominantly sand soil. Summer highs average 95°F, so Kohlrabi may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kohlrabi will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.
Putnam County Soil Profile
Soil Type
Sand
Soil pH
4.9-6.2
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 Putnam County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (4.9–6.2) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in Putnam County warms quickly in spring but drains fast. Kohlrabi will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Kohlrabi.
Organic Matter
Organic matter is low (1.4%). Add 2-3 inches of compost before planting Kohlrabi.
How to Plant Kohlrabi
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Sep 28 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 Kohlrabi
Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Kohlrabi Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | 3" | 2.6" | 0.4" | 💧 Light watering |
| Mar | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 2.3" | 0.7" | 💧 Light watering |
| May | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 7.9" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 9.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 7.4" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 2.2" | 0.8" | 💧 Light watering |
| Dec | 3" | 2.6" | 0.4" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Putnam County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kohlrabi 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.
Kohlrabi Planting Timeline — Putnam County, FL
Kohlrabi 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 | March 30 | Mar 30 – May 4 |
| Fall Sowing | October 7 | Oct 7 – Oct 21 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
296 days in Putnam County
Growing Tips for Kohlrabi in Putnam County
Direct sow Kohlrabi outdoors after February 09 in Putnam County when soil has warmed and frost danger has passed.
Sandy soil in Putnam County dries quickly — mulch Kohlrabi with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 297.0-day season in Putnam County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.
Common pests for Kohlrabi 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 spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.
Companion Planting
Good Companions
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Kohlrabi in Other Locations
Frequently Asked Questions
When should I plant Kohlrabi in Putnam County, FL?
Putnam County is in Zone 9a with an average last frost of February 9. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Putnam County, FL?
Putnam 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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