When to Plant Mizuna in Alamosa County, CO
May in Alamosa County, Colorado — your action list
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Get mizuna in the ground
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Direct-sow mizuna
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
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.
Alamosa County, Colorado is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 19, giving you a growing season of approximately 111 days.
At an elevation of 8,366 feet, Alamosa County receives approximately 18.3 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Mizuna to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mizuna successfully. Mulch heavily to conserve soil moisture.
Alamosa County Soil Profile
Soil Type
Loam
Soil pH
6.4-8
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 Alamosa County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (6.4–8.0) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Alamosa County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Mizuna.
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 05 to harvest before frost.
For a dedicated fall crop, sow by Jul 11.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 1.9" | 0" | ❄️ Dormant |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Alamosa 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 — Alamosa County, CO
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 26 | Apr 26 – May 10 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | July 5 | Jul 5 – Aug 2 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| 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 5a
📆 Growing Season
111 days in Alamosa County
Growing Tips for Mizuna in Alamosa County
Direct sow Mizuna outdoors after May 31 in Alamosa County when soil has warmed and frost danger has passed.
Common pests for Mizuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Alamosa County receives only 18" 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 Alamosa County, CO?
Alamosa County is in Zone 5a with an average last frost of May 31. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Alamosa County, CO?
Alamosa County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 19.
Your Alamosa County Garden Planner — Free
A 24-page printable planner built for Alamosa County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.