When to Plant Komatsuna in Skamania County, WA
Skamania County, Washington gardeners: here's your May plan
We've pulled the most time-sensitive tasks for Skamania County, Washington this May and put them front and centre. Tackle them in order.
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Time to start komatsuna inside
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Start harvesting komatsuna
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Looking ahead to June
- 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.
Skamania County, Washington is in USDA Zone 8a. The average last spring frost is April 18 and the first fall frost is October 19, giving you a growing season of approximately 184 days.
At an elevation of 16 feet, Skamania County receives approximately 43 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Komatsuna to ensure they mature before fall.
Skamania County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.2
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 Skamania County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (5.6–6.2) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Skamania County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Komatsuna will thrive.
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 Aug 30 to harvest before frost.
For a dedicated fall crop, sow by Aug 10.
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 | — | 6.5" | 0" | ❄️ Dormant |
| Feb | — | 4.3" | 0" | ❄️ Dormant |
| Mar | — | 3.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jun | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jul | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Aug | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 7.4" | 0" | ❄️ Dormant |
| Dec | — | 7.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Skamania 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 — Skamania County, WA
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 4 | Apr 4 – Apr 25 |
| Harvest | May 23 | May 23 – Jun 27 |
| Fall Sowing | August 10 | Aug 10 – Aug 24 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| 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
184 days in Skamania County
Growing Tips for Komatsuna in Skamania County
Direct sow Komatsuna outdoors after April 18 in Skamania County when soil has warmed and frost danger has passed.
Your generous 184.0-day season in Skamania 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 Skamania County, WA?
Skamania County is in Zone 8a with an average last frost of April 18. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Skamania County, WA?
Skamania County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 18 and first fall frost is October 19.
Your Skamania County Garden Planner — Free
A 24-page printable planner built for Skamania County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.