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When to Plant Bok Choy in Starr County, TX

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.

Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.

At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98ยฐF, so Bok Choy may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Bok Choy root diseases.

Starr County, TX (Zone 9b) Year-round
316 days
Last Spring Frost February 3
316 growing days
First Fall Frost December 16

Starr County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (249 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Mar 1 – Apr 5
Recommended (50%) ✓ Fits season (239 days to spare)
Start indoors: Jan 6 Transplant: Feb 3 🍅 Harvest: Mar 17 – Apr 21
Safe Start (90%) ✓ Fits season (220 days to spare)
Start indoors: Feb 3 Transplant: Mar 3 🍅 Harvest: Apr 14 – May 19

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 Starr County

How your county's soil matches Bok Choy's growing requirements.

Soil pH

Your soil pH (6.8โ€“7.5) is within Bok Choy's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Starr County is excellent for Bok Choy โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Bok Choy.

How to Plant Bok Choy

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Bok Choy

9
successive plantings in your 316-day season

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

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb 3" 1.9" 1.1" ๐Ÿ’ง Light watering
Mar 3" 3.4" 0" โœ… Rainfall sufficient
Apr 3" 6.6" 0" โœ… Rainfall sufficient
May 3" 8.8" 0" โœ… Rainfall sufficient
Jun 3" 7.6" 0" โœ… Rainfall sufficient
Jul 3" 7" 0" โœ… Rainfall sufficient
Aug 3" 6.4" 0" โœ… Rainfall sufficient
Sep 3" 4.9" 0" โœ… Rainfall sufficient
Oct 3" 4" 0" โœ… Rainfall sufficient
Nov 3" 1.6" 1.4" ๐Ÿ’ง Light watering
Dec 3" 1.6" 1.4" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Starr County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~1,175 GDD — county provides 7,449 GDD Excellent fit

Bok Choy Planting Timeline โ€” Starr County, TX

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors January 6 Jan 6 โ€“ Jan 20
Transplant Outdoors February 3 Feb 3 โ€“ Feb 17
Direct Sow January 13 Jan 13 โ€“ Feb 3
Harvest March 17 Mar 17 โ€“ Apr 21
Fall Sowing October 21 Oct 21 โ€“ Nov 4

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May โ€”
June โ€”
July โ€”
August โ€”
September โ€”
October Fall Sowing
November Fall Sowing
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

316 days in Starr County

Growing Tips for Bok Choy in Starr County

Direct sow Bok Choy outdoors after February 03 in Starr County when soil has warmed and frost danger has passed.

With summer highs reaching 98ยฐF in Starr County, provide afternoon shade for Bok Choy and water deeply in the morning.

Your generous 317.0-day season in Starr 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bok Choy in Starr County, TX?

Starr County is in Zone 9b with an average last frost of February 3. Plan your Bok Choy planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Starr County, TX?

Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Starr County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

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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 Starr County, TX. Local conditions may vary. Last updated: April 2026.