When to Plant Komatsuna in Horry County, SC
What to do in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
-
Bring in the komatsuna
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Coming up in June — start thinking about
- First harvests: komatsuna
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.
Horry County, South Carolina is in USDA Zone 8b. The average last spring frost is March 23 and the first fall frost is November 10, giving you a growing season of approximately 232 days.
At an elevation of 439 feet, Horry County receives approximately 53.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Komatsuna during the growing season. 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.
Horry County Soil Profile
Soil Type
Sandy Loam
Soil pH
4.9-5.9
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 Horry County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (4.9–5.9) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in Horry 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 low (1.8%). Add 2-3 inches of compost before planting 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 | — | 4.1" | 0" | ❄️ Dormant |
| Feb | — | 4.4" | 0" | ❄️ Dormant |
| Mar | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4" | 0.3" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Horry 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 — Horry County, SC
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 16 | Feb 16 – Mar 2 |
| Transplant Outdoors | March 23 | Mar 23 – Apr 6 |
| Direct Sow | March 9 | Mar 9 – Mar 30 |
| Harvest | April 27 | Apr 27 – Jun 1 |
| 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 | Harvest |
| 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
232 days in Horry County
Growing Tips for Komatsuna in Horry County
Direct sow Komatsuna outdoors after March 23 in Horry County when soil has warmed and frost danger has passed.
Sandy soil in Horry County dries quickly — mulch Komatsuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 232.0-day season in Horry 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 Horry County, SC?
Horry County is in Zone 8b with an average last frost of March 23. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Horry County, SC?
Horry County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 23 and first fall frost is November 10.
Your Horry County Garden Planner — Free
A 24-page printable planner built for Horry 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.