When to Plant Mustard Greens in Park County, WY
Park County, Wyoming gardeners: here's your May plan
May is a pivotal month for Park County, Wyoming gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Plant out mustard greens
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Plant mustard greens from seed, right in the garden
These tolerate cool soil, so you're not gambling by sowing now.
A few tasks this May that'll pay off in June
- Starting indoors: mustard greens
- First harvests: mustard greens
Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.
Park County, Wyoming is in USDA Zone 5a. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.
At an elevation of 6,993 feet, Park County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Mustard Greens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mustard Greens successfully. Mulch heavily to conserve soil moisture.
Park County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.2
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 Park County
How your county's soil matches Mustard Greens's growing requirements.
Soil pH
Your soil pH (6.8–8.2) is more alkaline than Mustard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Park County is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Mustard Greens.
How to Plant Mustard Greens
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mustard Greens
Sow every 3.4 weeks. Last sowing by Aug 03 to harvest before frost.
For a dedicated fall crop, sow by Jul 14.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Mustard Greens
Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Mustard Greens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1.8" | 0" | ❄️ Dormant |
| May | 3" | 2.1" | 0.9" | 💧 Light watering |
| Jun | 3" | 1.2" | 1.8" | 🚿 Regular watering |
| Jul | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Aug | 3" | 1.7" | 1.3" | 💧 Light watering |
| Sep | 3" | 1.2" | 1.8" | 🚿 Regular watering |
| Oct | — | 1.4" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Park County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mustard Greens 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.
Mustard Greens Planting Timeline — Park County, WY
Mustard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 16 | Apr 16 – Apr 30 |
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | June 25 | Jun 25 – Aug 27 |
| Fall Sowing | July 14 | Jul 14 – Jul 28 |
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 | Transplant Outdoors Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
124 days in Park County
Growing Tips for Mustard Greens in Park County
Direct sow Mustard Greens outdoors after May 21 in Park County when soil has warmed and frost danger has passed.
Common pests for Mustard Greens 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 early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mustard Greens in Other Locations
Frequently Asked Questions
When should I plant Mustard Greens in Park County, WY?
Park County is in Zone 5a with an average last frost of May 21. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Park County, WY?
Park County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 21 and first fall frost is September 22.
Your Park County Garden Planner — Free
A 24-page printable planner built for Park 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.