When to Plant Komatsuna in Routt County, CO
Top priorities for Routt County, Colorado gardeners in May
Your garden in Routt County, Colorado is working on a schedule, even when you're not. Here's where you should be this May.
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Scatter komatsuna into prepared beds
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Looking ahead to June
- Transplants going out: komatsuna
- Fall sowing: 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.
Routt County, Colorado is in USDA Zone 5a. The average last spring frost is June 12 and the first fall frost is September 8, giving you a growing season of approximately 88 days.
At an elevation of 5,381 feet, Routt County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Komatsuna to ensure they mature before fall.
Routt County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.9
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 Routt County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (6.7–7.9) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Routt County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Komatsuna.
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 Jul 20 to harvest before frost.
For a dedicated fall crop, sow by Jun 30.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | — | 2.8" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Aug | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Routt 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 — Routt County, CO
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 8 | May 8 – May 22 |
| Transplant Outdoors | June 12 | Jun 12 – Jun 26 |
| Direct Sow | May 29 | May 29 – Jun 19 |
| Harvest | July 17 | Jul 17 – Aug 21 |
| Fall Sowing | June 30 | Jun 30 – Jul 14 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
88 days in Routt County
Growing Tips for Komatsuna in Routt County
Direct sow Komatsuna outdoors after June 12 in Routt County when soil has warmed and frost danger has passed.
Common pests for Komatsuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Routt County receives only 24" of rain annually. Komatsuna needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Routt County, CO?
Routt County is in Zone 5a with an average last frost of June 12. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Routt County, CO?
Routt County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 12 and first fall frost is September 8.
Your Routt County Garden Planner — Free
A 24-page printable planner built for Routt 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.