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When to Plant Cardoon in Zapata County, TX

Zapata County, Texas Zone 9b May

May in the garden — Zapata County, Texas

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

Avg. last frost February 3
Avg. first frost December 14
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 13.3 hrs
A few tasks this May that'll pay off in June
  • First harvests: cardoon

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Cardoon is a large thistle relative of the artichoke, grown for its edible leaf stalks. It has dramatic silvery foliage and makes a striking ornamental as well.

Zapata County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 14, giving you a growing season of approximately 314 days.

At an elevation of 3,340 feet, Zapata County receives approximately 60.6 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Cardoon may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cardoon root diseases.

Zapata County, TX (Zone 9b) Year-round
314 days
Last Spring Frost February 3
314 growing days
First Fall Frost December 14
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Zapata County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Transplant: Jan 31 🍅 Harvest: Jun 6 – Jul 18
Recommended (50%) ✓ Fits season (132 days to spare)
Transplant: Feb 17 🍅 Harvest: Jun 23 – Aug 4
Safe Start (90%) ✓ Fits season (118 days to spare)
Transplant: Mar 13 🍅 Harvest: Jul 17 – Aug 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 Zapata County

How your county's soil matches Cardoon's growing requirements.

Soil pH

Your soil pH (6.2–7.6) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Cardoon.

How to Plant Cardoon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 538 gal / 100 sq ft

Monthly Watering Guide for Cardoon

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

Month Cardoon Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 4.3" 2.3" 2" 💧 Light watering
Mar 4.3" 4.1" 0.2" 💧 Light watering
Apr 4.3" 6.3" 0" ✅ Rainfall sufficient
May 4.3" 7.6" 0" ✅ Rainfall sufficient
Jun 4.3" 10.1" 0" ✅ Rainfall sufficient
Jul 4.3" 8.6" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.1" 0" ✅ Rainfall sufficient
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 4.3" 1.3" 3" 🚿 Regular watering

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

Cardoon 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.

Cardoon needs ~3,679 GDD — county provides 8,583 GDD Excellent fit

Cardoon Planting Timeline — Zapata County, TX

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors February 17 Feb 17 – Mar 3
Harvest June 23 Jun 23 – Aug 4

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April
May
June Harvest
July Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

120–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

314 days in Zapata County

Growing Tips for Cardoon in Zapata County

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

With summer highs reaching 103°F in Zapata County, provide afternoon shade for Cardoon and water deeply in the morning.

Common pests for Cardoon in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Blanch stalks by wrapping with cardboard or tying leaves together 3-4 weeks before harvest. Provide deep, rich soil and consistent moisture. Protect from hard frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cardoon in Zapata County, TX?

Zapata County is in Zone 9b with an average last frost of February 3. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Zapata County, TX?

Zapata County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 14.

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Your Zapata County Garden Planner — Free

A 24-page printable planner built for Zapata 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 Zapata 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.