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When to Plant Cardoon in Refugio County, TX

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.

Refugio County, Texas is in USDA Zone 9a. The average last spring frost is February 16 and the first fall frost is December 6, giving you a growing season of approximately 293 days.

At an elevation of 1,000 feet, Refugio County receives approximately 68.4 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, 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.

Refugio County, TX (Zone 9a) Year-round
293 days
Last Spring Frost February 16
293 growing days
First Fall Frost December 6

Refugio County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (118 days to spare)
Transplant: Feb 16 🍅 Harvest: Jun 22 – Aug 3
Recommended (50%) ✓ Fits season (111 days to spare)
Transplant: Mar 2 🍅 Harvest: Jul 6 – Aug 17
Safe Start (90%) ✓ Fits season (103 days to spare)
Transplant: Mar 26 🍅 Harvest: Jul 30 – Sep 10

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 Refugio County

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

Soil pH

Your soil pH (6.7โ€“7.2) is within Cardoon's preferred range (6.0โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.0%). 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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 60 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 โ€” 2" 0" โ„๏ธ Dormant
Feb 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Mar 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Apr 4.3" 8.3" 0" โœ… Rainfall sufficient
May 4.3" 9.2" 0" โœ… Rainfall sufficient
Jun 4.3" 11.3" 0" โœ… Rainfall sufficient
Jul 4.3" 9.3" 0" โœ… Rainfall sufficient
Aug 4.3" 8" 0" โœ… Rainfall sufficient
Sep 4.3" 5.7" 0" โœ… Rainfall sufficient
Oct 4.3" 4.5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Dec 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Refugio County). Supplement amounts are based on average rainfall โ€” 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" 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.

Cardoon needs ~3,679 GDD — county provides 8,011 GDD Excellent fit

Cardoon Planting Timeline โ€” Refugio County, TX

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors March 2 Mar 2 โ€“ Mar 16
Harvest July 6 Jul 6 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

120โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

293 days in Refugio County

Growing Tips for Cardoon in Refugio County

Direct sow Cardoon outdoors after February 16 in Refugio County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in Refugio 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 Refugio County, TX?

Refugio County is in Zone 9a with an average last frost of February 16. Plan your Cardoon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Refugio County, TX?

Refugio County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 16 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Refugio County gardeners in Zone 9a 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 Refugio County, TX. Local conditions may vary. Last updated: April 2026.