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When to Plant Broccoli Rabe in Callahan County, TX

Callahan County, Texas Zone 8a May

May in Callahan County, Texas — your action list

A quick May briefing for Callahan County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 21
Avg. first frost November 16
Soil temp (4") 56°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. It's harvest week for broccoli rabe

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to June
  • First harvests: broccoli rabe

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Broccoli rabe (rapini) is a brassica grown for its slightly bitter, nutty-flavored florets, leaves, and stems. It is a staple in Italian cooking.

Callahan County, Texas is in USDA Zone 8a. The average last spring frost is March 21 and the first fall frost is November 16, giving you a growing season of approximately 240 days.

At an elevation of 4,241 feet, Callahan County receives approximately 59.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Broccoli Rabe during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Broccoli Rabe root diseases.

Callahan County, TX (Zone 8a) Long season
240 days
Last Spring Frost March 21
240 growing days
First Fall Frost November 16

Callahan County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (167 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: Apr 21 – May 26
Recommended (50%) ✓ Fits season (163 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 2 – Jun 6
Safe Start (90%) ✓ Fits season (158 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: May 24 – Jun 28

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 Callahan County

How your county's soil matches Broccoli Rabe's growing requirements.

Soil pH

Your soil pH (6.8–7.4) is within Broccoli Rabe's preferred range (6.0–7.5).

Soil Texture

The loam soil in Callahan County is excellent for Broccoli Rabe — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Broccoli Rabe.

How to Plant Broccoli Rabe

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 Broccoli Rabe

7
successive plantings in your 240-day season

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

For a dedicated fall crop, sow by Sep 07.

Plant Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Broccoli Rabe

Broccoli Rabe needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Broccoli Rabe Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 3.5" 3.3" 0.2" 💧 Light watering
Apr 3.5" 5.9" 0" ✅ Rainfall sufficient
May 3.5" 7.8" 0" ✅ Rainfall sufficient
Jun 3.5" 11" 0" ✅ Rainfall sufficient
Jul 3.5" 8.5" 0" ✅ Rainfall sufficient
Aug 3.5" 6.1" 0" ✅ Rainfall sufficient
Sep 3.5" 5.7" 0" ✅ Rainfall sufficient
Oct 3.5" 3.8" 0" ✅ Rainfall sufficient
Nov 3.5" 1.8" 1.7" 💧 Light watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Callahan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Broccoli Rabe 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.

Broccoli Rabe needs ~912 GDD — county provides 4,380 GDD Excellent fit

Broccoli Rabe Planting Timeline — Callahan County, TX

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 – Feb 28
Transplant Outdoors March 21 Mar 21 – Apr 4
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 2 May 2 – Jun 6
Fall Sowing September 7 Sep 7 – Sep 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

240 days in Callahan County

Growing Tips for Broccoli Rabe in Callahan County

Direct sow Broccoli Rabe outdoors after March 21 in Callahan County when soil has warmed and frost danger has passed.

Your generous 240.0-day season in Callahan County allows multiple plantings of Broccoli Rabe. Sow every 20.0 days for continuous harvest.

Common pests for Broccoli Rabe 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. Harvest when small yellow flower buds first appear but before they open. Cut the main shoot first to encourage side shoots.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Broccoli Rabe in Callahan County, TX?

Callahan County is in Zone 8a with an average last frost of March 21. Plan your Broccoli Rabe planting based on this frost date — see the calendar above for exact timing.

What planting zone is Callahan County, TX?

Callahan County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 21 and first fall frost is November 16.

🌱

Your Callahan County Garden Planner — Free

A 24-page printable planner built for Callahan County (Zone 8a). 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 Callahan County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

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