When to Plant Bok Choy in Sac County, IA
Your May gardening checklist
Your Sac County, Iowa garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Begin indoor sowing: bok choy
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
Before June arrives, get these ready
- 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.
Sac County, Iowa is in USDA Zone 5a. The average last spring frost is April 25 and the first fall frost is October 8, giving you a growing season of approximately 166 days.
At an elevation of 1,221 feet, Sac County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Bok Choy to ensure they mature before fall.
Sac County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
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 Sac County
How your county's soil matches Bok Choy's growing requirements.
Soil pH
Your soil pH (5.9–6.7) overlaps with Bok Choy's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Sac 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 09 to harvest before frost.
For a dedicated fall crop, sow by Jul 30.
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 2.7" | 0.3" | 💧 Light watering |
| Oct | 3" | 2.6" | 0.4" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Sac 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 — Sac County, IA
Bok Choy Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | April 25 | Apr 25 – May 9 |
| Direct Sow | April 11 | Apr 11 – May 2 |
| Harvest | June 6 | Jun 6 – Jul 11 |
| Fall Sowing | July 30 | Jul 30 – Aug 13 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| 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
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
166 days in Sac County
Growing Tips for Bok Choy in Sac County
Direct sow Bok Choy outdoors after April 25 in Sac County when soil has warmed and frost danger has passed.
Your generous 166.0-day season in Sac 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 Sac County, IA?
Sac County is in Zone 5a with an average last frost of April 25. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sac County, IA?
Sac County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 25 and first fall frost is October 8.
Your Sac County Garden Planner — Free
A 24-page printable planner built for Sac County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.