When to Plant Bok Choy in Randolph County, IL
Your May planting checklist for Randolph County, Illinois
Here's what deserves your attention in Randolph County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Get bok choy seeds going inside
These need a head start before your last frost (April 11). Sow into cells now so you're ready to transplant in a few weeks.
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Pick bok choy
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
June will be here before you know it — start on
- First harvests: bok choy
Bok choy is a Chinese cabbage variety with crisp white stalks and dark green leaves. It is a fast-growing cool-season crop ideal for stir-fries and soups.
Randolph County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 20, giving you a growing season of approximately 192 days.
At an elevation of 501 feet, Randolph County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Bok Choy during the growing season.
Randolph County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Randolph County
How your county's soil matches Bok Choy's growing requirements.
Soil pH
Your soil pH (5.7–6.8) overlaps with Bok Choy's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Randolph County is excellent for Bok Choy — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Bok Choy will thrive.
How to Plant Bok Choy
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Bok Choy
Sow every 4.6 weeks. Last sowing by Aug 21 to harvest before frost.
For a dedicated fall crop, sow by Aug 11.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Bok Choy
Bok Choy needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Bok Choy Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.4" | 0.6" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Randolph County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Bok Choy 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.
Bok Choy Planting Timeline — Randolph County, IL
Bok Choy Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 7 | Mar 7 – Mar 21 |
| Transplant Outdoors | April 11 | Apr 11 – Apr 25 |
| Direct Sow | March 28 | Mar 28 – Apr 18 |
| Harvest | May 23 | May 23 – Jun 27 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
192 days in Randolph County
Growing Tips for Bok Choy in Randolph County
Direct sow Bok Choy outdoors after April 11 in Randolph County when soil has warmed and frost danger has passed.
Your generous 192.0-day season in Randolph County allows multiple plantings of Bok Choy. Sow every 20.0 days for continuous harvest.
Common pests for Bok Choy 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 for best results. Keep soil consistently moist. Harvest whole heads or cut outer leaves for a cut-and-come-again approach.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Bok Choy in Other Locations
Frequently Asked Questions
When should I plant Bok Choy in Randolph County, IL?
Randolph County is in Zone 7a with an average last frost of April 11. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.
What planting zone is Randolph County, IL?
Randolph County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 20.
Your Randolph County Garden Planner — Free
A 24-page printable planner built for Randolph County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.