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When to Plant Romanesco in Starr County, TX

Starr County, Texas Zone 9b May

May to-do list for Starr County, Texas

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

Avg. last frost February 3
Avg. first frost December 16
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.3 hrs
  1. It's harvest week for romanesco

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong June, finish these tasks
  • First harvests: romanesco

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Romanesco is a stunning brassica with a lime-green head composed of fractal-patterned spiraling florets. It has a nuttier, milder flavor than cauliflower.

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 98°F, so Romanesco may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Romanesco 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 (207 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Apr 5 – May 17
Recommended (50%) ✓ Fits season (197 days to spare)
Start indoors: Jan 6 Transplant: Feb 3 🍅 Harvest: Apr 21 – Jun 2
Safe Start (90%) ✓ Fits season (178 days to spare)
Start indoors: Feb 3 Transplant: Mar 3 🍅 Harvest: May 19 – Jun 30

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 Romanesco's growing requirements.

Soil pH

Your soil pH (6.8–7.5) is more alkaline than Romanesco prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Starr County is excellent for Romanesco — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Romanesco

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 Romanesco

5
successive plantings in your 316-day season

Sow every 8.6 weeks. Last sowing by Sep 07 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 901 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Romanesco

Romanesco needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Romanesco Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 4.3" 1.9" 2.4" 🚿 Regular watering
Mar 4.3" 3.4" 0.9" 💧 Light watering
Apr 4.3" 6.6" 0" ✅ Rainfall sufficient
May 4.3" 8.8" 0" ✅ Rainfall sufficient
Jun 4.3" 7.6" 0" ✅ Rainfall sufficient
Jul 4.3" 7" 0" ✅ Rainfall sufficient
Aug 4.3" 6.4" 0" ✅ Rainfall sufficient
Sep 4.3" 4.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 1.6" 2.7" 🚿 Regular watering
Dec 4.3" 1.6" 2.7" 🚿 Regular watering

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

Romanesco 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.

Romanesco needs ~2,056 GDD — county provides 7,449 GDD Excellent fit

Romanesco Planting Timeline — Starr County, TX

Romanesco Planting Calendar

Activity When Date Range
Start Indoors January 6 Jan 6 – Jan 20
Transplant Outdoors February 3 Feb 3 – Feb 17
Direct Sow January 13 Jan 13 – Feb 3
Harvest April 21 Apr 21 – Jun 2
Fall Sowing October 21 Oct 21 – Nov 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

316 days in Starr County

Growing Tips for Romanesco in Starr County

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

With summer highs reaching 98°F in Starr County, provide afternoon shade for Romanesco and water deeply in the morning.

Common pests for Romanesco in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 5-7 weeks before transplanting. Provide consistent moisture and avoid temperature stress. Harvest when head is fully formed but before florets begin to separate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Romanesco in Starr County, TX?

Starr County is in Zone 9b with an average last frost of February 3. Plan your Romanesco planting based on this frost date — 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.

🌱

Your Starr County Garden Planner — Free

A 24-page printable planner built for Starr 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.

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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: May 2026.

Sources & credits

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