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When to plant Pac Choi in McHenry County, IL

Aim to plant Pac Choi in McHenry County on or after April 4; the window stays open through April 25. McHenry County's 185-day frost-free season gives you enough for a full main crop and a short fall succession. A second sowing from August 11 to August 25 extends the harvest into fall.

When to Plant Pac Choi in McHenry County, IL

McHenry County, Illinois Zone 5b June

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Avg. last frost April 18
Avg. first frost October 20
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15.1 hrs

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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.

McHenry County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.

At an elevation of 640 feet, McHenry County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Pac Choi to ensure they mature before fall.

McHenry County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 18
185 growing days
First Fall Frost October 20

McHenry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Pac Choi Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: May 25 – Jun 22
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: May 30 – Jun 27
Safe Start (90%) ✓ Fits season (114 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 15 – Jul 13

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 McHenry County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Pac Choi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Pac Choi will thrive.

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

5
successive plantings in your 185-day season

Sow every 4.6 weeks. Last sowing by Aug 26 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Pac Choi Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,196 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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 6.5" 4.2" 2.3" 💧 Light watering
May 6.5" 4.2" 2.3" 💧 Light watering
Jun 6.5" 4.8" 1.7" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 4.5" 2" 💧 Light watering
Sep 6.5" 3.3" 3.2" 💧 Light watering
Oct 6.5" 3.4" 3.1" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in McHenry 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 2,405 GDD Excellent fit

Pac Choi Planting Timeline — McHenry County, IL

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest May 30 May 30 – Jun 27
Fall Sowing August 11 Aug 11 – Aug 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July
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 5b

📆 Growing Season

185 days in McHenry County

Growing Tips for Pac Choi in McHenry County

Direct sow Pac Choi outdoors after April 18 in McHenry County when soil has warmed and frost danger has passed.

Your generous 185.0-day season in McHenry County allows multiple plantings of Pac Choi. Sow every 20.0 days for continuous harvest.

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.

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 McHenry County, IL?

McHenry County is in Zone 5b with an average last frost of April 18. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.

What planting zone is McHenry County, IL?

McHenry County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 20.

When should I plant Pac Choi in McHenry County, IL?

In McHenry County, IL, plant Pac Choi after the last frost (around April 18) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is McHenry County, IL for Pac Choi?

McHenry County sits in USDA Zone 5b. Pac Choi grows reliably in zones 2a through 11b, so it's a good fit here.

Can Pac Choi grow in McHenry County's climate?

Yes — Pac Choi grows well in McHenry County's temperate climate. McHenry County averages a 185-day frost-free season, with last frost around April 18 and first frost around October 20.

🌱

Your McHenry County Garden Planner — Free

A 22-page printable planner built for McHenry 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.

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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 McHenry County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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