When to Plant Mizuna in Douglas County, WA
Top priorities for Douglas County, Washington gardeners in May
Your garden in Douglas County, Washington is working on a schedule, even when you're not. Here's where you should be this May.
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Time to transplant mizuna
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
Looking ahead to June
- Starting indoors: mizuna
- 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.
Douglas County, Washington is in USDA Zone 7a. The average last spring frost is May 8 and the first fall frost is October 4, giving you a growing season of approximately 149 days.
At an elevation of 2,920 feet, Douglas County receives approximately 15.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Mizuna during the growing season. With low rainfall, drip irrigation is essential for growing Mizuna successfully. Mulch heavily to conserve soil moisture.
Douglas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.2
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 Douglas County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (5.5–6.2) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Douglas County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — 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 Aug 20 to harvest before frost.
For a dedicated fall crop, sow by Jul 26.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 2.2" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 1.2" | 0" | ❄️ Dormant |
| May | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jun | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jul | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Aug | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Sep | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Oct | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Douglas 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 — Douglas County, WA
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Harvest | June 12 | Jun 12 – Jul 10 |
| Fall Sowing | July 26 | Jul 26 – Aug 9 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
149 days in Douglas County
Growing Tips for Mizuna in Douglas County
Direct sow Mizuna outdoors after May 08 in Douglas County when soil has warmed and frost danger has passed.
Your generous 149.0-day season in Douglas 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.
Douglas County receives only 16" of rain annually. Mizuna needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Douglas County, WA?
Douglas County is in Zone 7a with an average last frost of May 8. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Douglas County, WA?
Douglas County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 8 and first fall frost is October 4.
Your Douglas County Garden Planner — Free
A 24-page printable planner built for Douglas County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.