When to Plant Mizuna in Wahkiakum County, WA
This month in Wahkiakum County, Washington
Here's what deserves your attention in Wahkiakum County, Washington this month. Everything below is tailored to Zone 8b and timed around your local frost dates.
-
Fire up the seed-starting tray: mizuna
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
-
Basket week: mizuna
If you can't use it all right away, check the food-preservation section of your planner.
June will be here before you know it — start on
- First harvests: mizuna
Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.
Wahkiakum County, Washington is in USDA Zone 8b. The average last spring frost is April 13 and the first fall frost is November 4, giving you a growing season of approximately 205 days.
At an elevation of 180 feet, Wahkiakum County receives approximately 35.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Mizuna during the growing season.
Wahkiakum County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.3
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 Wahkiakum County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (5.4–6.3) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Wahkiakum County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.6%) — Mizuna will thrive.
How to Plant Mizuna
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Sep 20 to harvest before frost.
For a dedicated fall crop, sow by Aug 26.
Plant Water Budget
Monthly Watering Guide for Mizuna
Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mizuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.9" | 0" | ❄️ Dormant |
| Feb | — | 4.2" | 0" | ❄️ Dormant |
| Mar | — | 3.6" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| May | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jun | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Jul | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Aug | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Dec | — | 5.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Wahkiakum County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mizuna 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.
Mizuna Planting Timeline — Wahkiakum County, WA
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | May 18 | May 18 – Jun 15 |
| Fall Sowing | August 26 | Aug 26 – Sep 9 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
205 days in Wahkiakum County
Growing Tips for Mizuna in Wahkiakum County
Direct sow Mizuna outdoors after April 13 in Wahkiakum County when soil has warmed and frost danger has passed.
Your generous 205.0-day season in Wahkiakum County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.
Common pests for Mizuna 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. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mizuna in Other Locations
Frequently Asked Questions
When should I plant Mizuna in Wahkiakum County, WA?
Wahkiakum County is in Zone 8b with an average last frost of April 13. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Wahkiakum County, WA?
Wahkiakum County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 13 and first fall frost is November 4.
Your Wahkiakum County Garden Planner — Free
A 24-page printable planner built for Wahkiakum 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.