When to Plant Komatsuna in Barnwell County, SC
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Basket week: komatsuna
If you can't use it all right away, check the food-preservation section of your planner.
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.
Barnwell County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 10, giving you a growing season of approximately 233 days.
At an elevation of 157 feet, Barnwell County receives approximately 48.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°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.
Barnwell County Soil Profile
Soil Type
Sandy Loam
Soil pH
5-6.3
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 Barnwell County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (5.0–6.3) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in Barnwell County warms quickly in spring but drains fast. Komatsuna will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Komatsuna.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Komatsuna.
How to Plant Komatsuna
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Komatsuna
Sow every 4 weeks. Last sowing by Sep 21 to harvest before frost.
For a dedicated fall crop, sow by Sep 01.
Plant Water Budget
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 | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 4.1" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Barnwell County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Komatsuna 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.
Komatsuna Planting Timeline — Barnwell County, SC
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Direct Sow | March 8 | Mar 8 – Mar 29 |
| Harvest | April 26 | Apr 26 – May 31 |
| Fall Sowing | September 1 | Sep 1 – Sep 15 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
233 days in Barnwell County
Growing Tips for Komatsuna in Barnwell County
Direct sow Komatsuna outdoors after March 22 in Barnwell County when soil has warmed and frost danger has passed.
Sandy soil in Barnwell County dries quickly — mulch Komatsuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 97°F in Barnwell County, provide afternoon shade for Komatsuna and water deeply in the morning.
Your generous 233.0-day season in Barnwell County allows multiple plantings of Komatsuna. Sow every 17.0 days for continuous harvest.
Common pests for Komatsuna 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. 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 Barnwell County, SC?
Barnwell County is in Zone 8b with an average last frost of March 22. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Barnwell County, SC?
Barnwell County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 10.
Your Barnwell County Garden Planner — Free
A 24-page printable planner built for Barnwell County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.