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When to Plant Mustard Greens in Summit County, UT

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.

Summit County, Utah is in USDA Zone 5a. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.

At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Mustard Greens during the growing season.

Summit County, UT (Zone 5a) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Jul 4 – Sep 5
Recommended (50%) ✗ May not fit
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Jul 15 – Sep 16
Safe Start (90%) ✓ Fits season (3 days to spare)
Start indoors: May 17 Transplant: Jun 21 🍅 Harvest: Jul 26 – Sep 27

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 Summit County

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (6.4โ€“8.3) is more alkaline than Mustard Greens prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Summit County is excellent for Mustard Greens โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Mustard Greens.

How to Plant Mustard Greens

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mustard Greens

3
successive plantings in your 94-day season

Sow every 3.4 weeks. Last sowing by Jul 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 04.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 2.9" 0" โ„๏ธ Dormant
May โ€” 2.9" 0" โ„๏ธ Dormant
Jun 3" 1.8" 1.2" ๐Ÿ’ง Light watering
Jul 3" 1.9" 1.1" ๐Ÿ’ง Light watering
Aug 3" 2.5" 0.5" ๐Ÿ’ง Light watering
Sep 3" 2" 1" ๐Ÿ’ง Light watering
Oct โ€” 2.1" 0" โ„๏ธ Dormant
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Summit County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~580 GDD — county provides 1,363 GDD Excellent fit

Mustard Greens Planting Timeline โ€” Summit County, UT

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors May 6 May 6 โ€“ May 20
Transplant Outdoors June 10 Jun 10 โ€“ Jun 24
Direct Sow May 27 May 27 โ€“ Jun 17
Harvest July 15 Jul 15 โ€“ Sep 16
Fall Sowing July 4 Jul 4 โ€“ Jul 18

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Start Indoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

30โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

94 days in Summit County

Growing Tips for Mustard Greens in Summit County

Direct sow Mustard Greens outdoors after June 10 in Summit 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Summit County, UT?

Summit County is in Zone 5a with an average last frost of June 10. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Summit County, UT?

Summit County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is June 10 and first fall frost is September 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Summit County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Summit County, UT. Local conditions may vary. Last updated: April 2026.