When to Plant Mizuna in Valley County, MT
Your May planting checklist for Valley County, Montana
We've pulled the most time-sensitive tasks for Valley County, Montana this May and put them front and centre. Tackle them in order.
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Get mizuna in the ground
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Seed mizuna outdoors
Your soil is 25°F — warm enough for these to germinate without babying.
Coming up in June — start thinking about
- Starting indoors: mizuna
- First harvests: mizuna
- Fall sowing: 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.
Valley County, Montana is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 21, giving you a growing season of approximately 131 days.
At an elevation of 8,293 feet, Valley County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Mizuna to ensure they mature before fall.
Valley County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.2
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 Valley County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (6.6–8.2) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Valley County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Mizuna.
How to Plant Mizuna
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Aug 07 to harvest before frost.
For a dedicated fall crop, sow by Jun 29.
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Jun | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Aug | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Sep | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Oct | — | 1.8" | 0" | ❄️ Dormant |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Valley 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 — Valley County, MT
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 1 | Apr 1 – Apr 15 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | June 17 | Jun 17 – Jul 15 |
| Fall Sowing | June 29 | Jun 29 – Jul 13 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing Harvest |
| July | Fall Sowing Harvest |
| August | — |
| 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: acceptable
🗺️ USDA Zone
Zone 4a
📆 Growing Season
131 days in Valley County
Growing Tips for Mizuna in Valley County
Direct sow Mizuna outdoors after May 13 in Valley County when soil has warmed and frost danger has passed.
Your generous 131.0-day season in Valley 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.
Valley County receives only 23" 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 Valley County, MT?
Valley County is in Zone 4a with an average last frost of May 13. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Valley County, MT?
Valley County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 21.
Your Valley County Garden Planner — Free
A 24-page printable planner built for Valley County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.