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When to Plant Cardoon in Hays County, TX

Hays County, Texas Zone 9a May

Your May planting checklist for Hays County, Texas

Here's what deserves your attention in Hays County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 6
Avg. first frost November 22
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 13.5 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.

Hays County, Texas is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 22, giving you a growing season of approximately 261 days.

At an elevation of 3,119 feet, Hays County receives approximately 61.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Cardoon during the growing season. Clay soil retains moisture well for Cardoon, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cardoon root diseases.

Hays County, TX (Zone 9a) Long season
261 days
Last Spring Frost March 6
261 growing days
First Fall Frost November 22
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Hays County Soil Profile

Soil Type

Clay

Soil pH

7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Transplant: Mar 10 🍅 Harvest: Jul 14 – Aug 25
Recommended (50%) ✓ Fits season (79 days to spare)
Transplant: Mar 20 🍅 Harvest: Jul 24 – Sep 4
Safe Start (90%) ✓ Fits season (71 days to spare)
Transplant: Apr 16 🍅 Harvest: Aug 20 – Oct 1

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 Hays County

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

Soil pH

Your soil pH (7.0–8.0) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.

Soil Texture

Heavy clay soil (45% clay) in Hays County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.8%). 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 13 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 1.6" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 6.5" 0" ✅ Rainfall sufficient
May 4.3" 9.5" 0" ✅ Rainfall sufficient
Jun 4.3" 9.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7" 0" ✅ Rainfall sufficient
Aug 4.3" 8.1" 0" ✅ Rainfall sufficient
Sep 4.3" 5.1" 0" ✅ Rainfall sufficient
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Hays 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 ~2,362 GDD — county provides 4,567 GDD Excellent fit

Cardoon Planting Timeline — Hays County, TX

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors March 20 Mar 20 – Apr 3
Harvest July 24 Jul 24 – Sep 4

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April Transplant Outdoors
May
June
July Harvest
August Harvest
September Harvest
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 9a

📆 Growing Season

261 days in Hays County

Growing Tips for Cardoon in Hays County

Direct sow Cardoon outdoors after March 06 in Hays County when soil has warmed and frost danger has passed.

With Hays County's clay soil (45% clay), work in 3-4 inches of compost before planting Cardoon. Avoid tilling when soil is wet to prevent compaction.

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 Hays County, TX?

Hays County is in Zone 9a with an average last frost of March 6. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hays County, TX?

Hays County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 22.

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Your Hays County Garden Planner — Free

A 24-page printable planner built for Hays 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 Hays 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.