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When to Plant Mustard Greens in Sanpete County, UT

Sanpete County, Utah Zone 6a May

Sanpete County, Utah gardeners: here's your May plan

Each item below is timed to Sanpete County, Utah's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 21
Avg. first frost September 28
Soil temp (4") 38°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Move mustard greens from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Seed mustard greens outdoors

    Your soil is 38°F — warm enough for these to germinate without babying.

Looking ahead to June
  • Starting indoors: mustard greens
  • First harvests: mustard greens

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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.

Sanpete County, Utah is in USDA Zone 6a. The average last spring frost is May 21 and the first fall frost is September 28, giving you a growing season of approximately 130 days.

At an elevation of 6,969 feet, Sanpete County receives approximately 14.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Mustard Greens during the growing season. With low rainfall, drip irrigation is essential for growing Mustard Greens successfully. Mulch heavily to conserve soil moisture.

Sanpete County, UT (Zone 6a) Short season
130 days
Last Spring Frost May 21
130 growing days
First Fall Frost September 28

Sanpete County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 17 – Aug 19
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Apr 16 Transplant: May 21 🍅 Harvest: Jun 25 – Aug 27
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Jul 15 – Sep 16

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 Sanpete County

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

Soil pH

Your soil pH (6.5–7.8) 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 Sanpete County is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). 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

5
successive plantings in your 130-day season

Sow every 3.4 weeks. Last sowing by Aug 09 to harvest before frost.

For a dedicated fall crop, sow by Jul 20.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 335 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 3" 1.7" 1.3" 💧 Light watering
Jun 3" 1" 2" 🚿 Regular watering
Jul 3" 1.4" 1.6" 🚿 Regular watering
Aug 3" 1.5" 1.5" 🚿 Regular watering
Sep 3" 1.3" 1.7" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Sanpete 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 needs ~580 GDD — county provides 1,885 GDD Excellent fit

Mustard Greens Planting Timeline — Sanpete County, UT

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 20 Jul 20 – Aug 3

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Harvest
July Fall Sowing Harvest
August Fall Sowing 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 6a

📆 Growing Season

130 days in Sanpete County

Growing Tips for Mustard Greens in Sanpete County

Direct sow Mustard Greens outdoors after May 21 in Sanpete County when soil has warmed and frost danger has passed.

Your generous 130.0-day season in Sanpete County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.

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 Sanpete County, UT?

Sanpete County is in Zone 6a 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 Sanpete County, UT?

Sanpete County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 21 and first fall frost is September 28.

🌱

Your Sanpete County Garden Planner — Free

A 24-page printable planner built for Sanpete County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.