When to plant Komatsuna in St. Johns County, FL
St. Johns County's climate puts the Komatsuna spring window between January 19 and February 9. aim for a steady week of warm soil before planting. A second sowing from October 7 to October 21 extends the harvest into fall.
When to Plant Komatsuna in St. Johns County, FL
Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.
St. Johns County, Florida is in USDA Zone 9b. 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 Komatsuna may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Komatsuna will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Komatsuna root diseases.
St. Johns County Soil Profile
Soil Type
Sand
Soil pH
4.9-6.1
Drainage
Well Drained
Monthly Watering Guide for Komatsuna
Komatsuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Komatsuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Mar | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jun | 4.3" | 7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.9" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Dec | 4.3" | 2.3" | 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.
Komatsuna Planting Timeline — St. Johns County, FL
Komatsuna 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 16 | Mar 16 – Apr 20 |
| Fall Sowing | October 7 | Oct 7 – Oct 21 |
Plant 0.5" deep · 6" 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 | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 9b
📆 Growing Season
296 days in St. Johns County
Growing Tips for St. Johns County
Direct sow in spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Komatsuna in Other Locations
Frequently Asked Questions
When should I plant Komatsuna in St. Johns County, FL?
St. Johns County is in Zone 9b with an average last frost of February 9. Plan your Komatsuna 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 9b. The average last spring frost is February 9 and first fall frost is December 2.
When should I plant Komatsuna in St. Johns County, FL?
In St. Johns County, FL, plant Komatsuna after the last frost (around February 9) and before the first frost (around December 2). Best results when soil holds above 50°F.
What growing zone is St. Johns County, FL for Komatsuna?
St. Johns County sits in USDA Zone 9b. Komatsuna grows reliably in zones 2a through 11b, so it's a good fit here.
Can Komatsuna grow in St. Johns County's climate?
Yes — Komatsuna grows well in St. Johns County's temperate climate. St. Johns County averages a 297-day frost-free season, with last frost around February 9 and first frost around December 2.
Your St. Johns County Garden Planner — Free
A 22-page printable planner built for St. Johns 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.