Blog

When to Plant Pac Choi in Clark County, ID

Clark County, Idaho Zone 5b May

What to do in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost June 7
Avg. first frost September 10
Soil temp (4") 32°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Sow pac choi where they'll grow

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

Coming up in June — start thinking about
  • Transplants going out: pac choi

Instant PDF download. No spam, unsubscribe any time.

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.

Clark County, Idaho is in USDA Zone 5b. The average last spring frost is June 7 and the first fall frost is September 10, giving you a growing season of approximately 95 days.

At an elevation of 7,493 feet, Clark County receives approximately 21.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Pac Choi to ensure they mature before fall.

Clark County, ID (Zone 5b) Very short season
95 days
Last Spring Frost June 7
95 growing days
First Fall Frost September 10
Share this guide:

Clark County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Jul 4 – Aug 1
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: May 3 Transplant: Jun 7 🍅 Harvest: Jul 19 – Aug 16
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: May 17 Transplant: Jun 21 🍅 Harvest: Aug 2 – Aug 30

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 Clark County

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

Soil pH

Your soil pH (6.8–7.8) overlaps with Pac Choi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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

2
successive plantings in your 95-day season

Sow every 4.6 weeks. Last sowing by Jul 17 to harvest before frost.

For a dedicated fall crop, sow by Jul 02.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 540 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 6.5" 1.5" 5" 🚿 Regular watering
Jul 6.5" 1.7" 4.8" 🚿 Regular watering
Aug 6.5" 2.2" 4.3" 🚿 Regular watering
Sep 6.5" 1.7" 4.8" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Clark 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 ~546 GDD — county provides 1,092 GDD Excellent fit

Pac Choi Planting Timeline — Clark County, ID

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors May 3 May 3 – May 17
Transplant Outdoors June 7 Jun 7 – Jun 21
Direct Sow May 24 May 24 – Jun 14
Harvest July 19 Jul 19 – Aug 16
Fall Sowing July 2 Jul 2 – Jul 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

40–55 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

95 days in Clark County

Growing Tips for Pac Choi in Clark County

Direct sow Pac Choi outdoors after June 07 in Clark 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.

Clark County receives only 22" 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 Clark County, ID?

Clark County is in Zone 5b with an average last frost of June 7. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, ID?

Clark County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 7 and first fall frost is September 10.

🌱

Your Clark County Garden Planner — Free

A 24-page printable planner built for Clark County (Zone 5b). 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 Clark County, ID. 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.