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When to Plant Pac Choi in Carbon County, UT

Carbon County, Utah Zone 6a May

Your May planting checklist for Carbon County, Utah

We've pulled the most time-sensitive tasks for Carbon County, Utah this May and put them front and centre. Tackle them in order.

Avg. last frost May 17
Avg. first frost September 27
Soil temp (4") 43°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Get pac choi in the ground

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Seed pac choi outdoors

    These tolerate cool soil, so you're not gambling by sowing now.

June prep starts now
  • Starting indoors: pac choi
  • First harvests: pac choi

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Pac choi (baby bok choy) is a compact variety of Chinese cabbage with tender leaves and crisp stems. It grows quickly and is ideal for containers and small spaces.

Carbon County, Utah is in USDA Zone 6a. The average last spring frost is May 17 and the first fall frost is September 27, giving you a growing season of approximately 133 days.

At an elevation of 5,755 feet, Carbon County receives approximately 14.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Pac Choi to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Pac Choi successfully. Mulch heavily to conserve soil moisture.

Carbon County, UT (Zone 6a) Short season
133 days
Last Spring Frost May 17
133 growing days
First Fall Frost September 27

Carbon County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jun 18 – Jul 16
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jun 28 – Jul 26
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: May 4 Transplant: Jun 8 🍅 Harvest: Jul 20 – Aug 17

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 Carbon County

How your county's soil matches Pac Choi's growing requirements.

Soil pH

Your soil pH (6.4–8.3) overlaps with Pac Choi's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Carbon County is excellent for Pac Choi — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Pac Choi.

How to Plant Pac Choi

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Pac Choi

3
successive plantings in your 133-day season

Sow every 4.6 weeks. Last sowing by Aug 03 to harvest before frost.

For a dedicated fall crop, sow by Jul 19.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 1,494 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Pac Choi

Pac Choi needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Pac Choi Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 6.5" 1.8" 4.7" 🚿 Regular watering
Jun 6.5" 1.1" 5.4" 🚿 Regular watering
Jul 6.5" 1.3" 5.2" 🚿 Regular watering
Aug 6.5" 1.3" 5.2" 🚿 Regular watering
Sep 6.5" 1.1" 5.4" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Carbon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pac Choi 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.

Pac Choi needs ~618 GDD — county provides 1,729 GDD Excellent fit

Pac Choi Planting Timeline — Carbon County, UT

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 – Apr 26
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 3 May 3 – May 24
Harvest June 28 Jun 28 – Jul 26
Fall Sowing July 19 Jul 19 – Aug 2

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

40–55 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

133 days in Carbon County

Growing Tips for Pac Choi in Carbon County

Direct sow Pac Choi outdoors after May 17 in Carbon County when soil has warmed and frost danger has passed.

Common pests for Pac Choi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Carbon County receives only 14" of rain annually. Pac Choi needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in spring or fall. Grows best in cool weather. Space 6 inches apart for baby pac choi. Harvest whole plants or cut outer leaves as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pac Choi in Carbon County, UT?

Carbon County is in Zone 6a with an average last frost of May 17. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carbon County, UT?

Carbon County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 17 and first fall frost is September 27.

🌱

Your Carbon County Garden Planner — Free

A 24-page printable planner built for Carbon 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Carbon 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.