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When to Plant Cardoon in Atascosa County, TX

Atascosa County, Texas Zone 9a May

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Avg. last frost February 26
Avg. first frost November 29
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 13.4 hrs

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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.

Atascosa County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 29, giving you a growing season of approximately 276 days.

At an elevation of 1,942 feet, Atascosa County receives approximately 51.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Cardoon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cardoon root diseases.

Atascosa County, TX (Zone 9a) Year-round
276 days
Last Spring Frost February 26
276 growing days
First Fall Frost November 29

Atascosa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Transplant: Feb 27 🍅 Harvest: Jul 3 – Aug 14
Recommended (50%) ✓ Fits season (94 days to spare)
Transplant: Mar 12 🍅 Harvest: Jul 16 – Aug 27
Safe Start (90%) ✓ Fits season (87 days to spare)
Transplant: Apr 5 🍅 Harvest: Aug 9 – Sep 20

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 Atascosa County

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

Soil pH

Your soil pH (6.8–7.7) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cardoon.

Organic Matter

Organic matter is moderate (2.1%). 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
0.5″/week
Watering frequency 1-2 times/week
Season total 1,272 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 1.5" 0" ❄️ Dormant
Feb 4.3" 1.6" 2.7" 🚿 Regular watering
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 4.8" 0" ✅ Rainfall sufficient
May 4.3" 7.6" 0" ✅ Rainfall sufficient
Jun 4.3" 7.4" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 6.6" 0" ✅ Rainfall sufficient
Sep 4.3" 4.9" 0" ✅ Rainfall sufficient
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Atascosa 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 ~2,464 GDD — county provides 5,055 GDD Excellent fit

Cardoon Planting Timeline — Atascosa County, TX

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors March 12 Mar 12 – Mar 26
Harvest July 16 Jul 16 – Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

120–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

276 days in Atascosa County

Growing Tips for Cardoon in Atascosa County

Direct sow Cardoon outdoors after February 26 in Atascosa County when soil has warmed and frost danger has passed.

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 Atascosa County, TX?

Atascosa County is in Zone 9a with an average last frost of February 26. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Atascosa County, TX?

Atascosa County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 29.

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Your Atascosa County Garden Planner — Free

A 24-page printable planner built for Atascosa County (Zone 9a). 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 Atascosa 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.