When to Plant Komatsuna in Washington County, AL
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.
Washington County, Alabama is in USDA Zone 8a. The average last spring frost is March 12 and the first fall frost is November 13, giving you a growing season of approximately 246 days.
At an elevation of 419 feet, Washington County receives approximately 54.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Komatsuna may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Komatsuna, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Komatsuna root diseases.
Washington County Soil Profile
Soil Type
Clay Loam
Soil pH
5.3-6.6
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 Washington County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (5.3–6.6) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The clay loam soil in Washington County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). 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 24 to harvest before frost.
For a dedicated fall crop, sow by Sep 04.
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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 5.1" | 0" | ❄️ Dormant |
| Mar | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| May | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Dec | — | 5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Washington 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 — Washington County, AL
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | March 12 | Mar 12 – Mar 26 |
| Direct Sow | February 26 | Feb 26 – Mar 19 |
| Harvest | April 16 | Apr 16 – May 21 |
| Fall Sowing | September 4 | Sep 4 – Sep 18 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8a
📆 Growing Season
246 days in Washington County
Growing Tips for Komatsuna in Washington County
Direct sow Komatsuna outdoors after March 12 in Washington County when soil has warmed and frost danger has passed.
With Washington County's clay soil (34% clay), work in 3-4 inches of compost before planting Komatsuna. Avoid tilling when soil is wet to prevent compaction.
With summer highs reaching 97°F in Washington County, provide afternoon shade for Komatsuna and water deeply in the morning.
Your generous 246.0-day season in Washington 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 Washington County, AL?
Washington County is in Zone 8a with an average last frost of March 12. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, AL?
Washington County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 12 and first fall frost is November 13.
Plan Your Garden with Confidence
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