When to Plant Bok Choy in San Benito County, CA
Your May planting checklist for San Benito County, California
Here's what deserves your attention in San Benito County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
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Collect bok choy at their peak
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
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.
San Benito County, California is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is November 29, giving you a growing season of approximately 281 days.
At an elevation of 149 feet, San Benito County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Bok Choy during the growing season. With low rainfall, drip irrigation is essential for growing Bok Choy successfully. Mulch heavily to conserve soil moisture.
San Benito County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.4
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 San Benito County
How your county's soil matches Bok Choy's growing requirements.
Soil pH
Your soil pH (6.5–7.4) is within Bok Choy's preferred range (6.0–7.5).
Soil Texture
The loam soil in San Benito County is excellent for Bok Choy — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Bok Choy.
How to Plant Bok Choy
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Bok Choy
Sow every 4.6 weeks. Last sowing by Sep 30 to harvest before frost.
For a dedicated fall crop, sow by Oct 04.
Plant Water Budget
Water stress score is 10/10 — 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 | — | 2.5" | 0" | ❄️ Dormant |
| Feb | 3" | 2.6" | 0.4" | 💧 Light watering |
| Mar | 3" | 2.2" | 0.8" | 💧 Light watering |
| Apr | 3" | 1.1" | 1.9" | 🚿 Regular watering |
| May | 3" | 0.3" | 2.7" | 🚿 Regular watering |
| Jun | 3" | 0.1" | 2.9" | 🚿 Regular watering |
| Jul | 3" | 0" | 3" | 🚿 Regular watering |
| Aug | 3" | 0" | 3" | 🚿 Regular watering |
| Sep | 3" | 0.1" | 2.9" | 🚿 Regular watering |
| Oct | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| Nov | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in San Benito 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 — San Benito County, CA
Bok Choy Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 24 | Jan 24 – Feb 7 |
| Transplant Outdoors | February 21 | Feb 21 – Mar 7 |
| Direct Sow | January 31 | Jan 31 – Feb 21 |
| Harvest | April 4 | Apr 4 – May 9 |
| Fall Sowing | October 4 | Oct 4 – Oct 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · 1-2 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
281 days in San Benito County
Growing Tips for Bok Choy in San Benito County
Direct sow Bok Choy outdoors after February 21 in San Benito County when soil has warmed and frost danger has passed.
Your generous 282.0-day season in San Benito 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 San Benito County, CA?
San Benito County is in Zone 9b with an average last frost of February 21. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Benito County, CA?
San Benito County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is November 29.
Your San Benito County Garden Planner — Free
A 24-page printable planner built for San Benito County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.