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When to Plant Cardoon in Maricopa County, AZ

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.

Maricopa County, Arizona is in USDA Zone 9b. The average last spring frost is January 31 and the first fall frost is December 6, giving you a growing season of approximately 309 days.

At an elevation of 4,014 feet, Maricopa County receives approximately 12.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 108ยฐF, so Cardoon may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Cardoon will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Cardoon successfully. Mulch heavily to conserve soil moisture.

Maricopa County, AZ (Zone 9b) Year-round
309 days
Last Spring Frost January 31
309 growing days
First Fall Frost December 6

Maricopa County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (136 days to spare)
Transplant: Jan 31 🍅 Harvest: Jun 6 – Jul 18
Recommended (50%) ✓ Fits season (127 days to spare)
Transplant: Feb 14 🍅 Harvest: Jun 20 – Aug 1
Safe Start (90%) ✓ Fits season (122 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 Maricopa County

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

Soil pH

Your soil pH (7.2โ€“8.5) is more alkaline than Cardoon prefers (6.0โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Maricopa County warms quickly in spring but drains fast. Cardoon will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Cardoon.

How to Plant Cardoon

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,750 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

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 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Feb 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Mar 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Apr 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
May 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Jun 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Jul 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Aug 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Sep 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Oct 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Nov 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Dec 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Janโ€“Dec in Maricopa 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 ~4,185 GDD — county provides 9,610 GDD Excellent fit

Cardoon Planting Timeline โ€” Maricopa County, AZ

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors February 14 Feb 14 โ€“ Feb 28
Harvest June 20 Jun 20 โ€“ Aug 1

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March โ€”
April โ€”
May โ€”
June Harvest
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 2-3 times/week

๐Ÿ“… Days to Maturity

120โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

309 days in Maricopa County

Growing Tips for Cardoon in Maricopa County

Direct sow Cardoon outdoors after January 31 in Maricopa County when soil has warmed and frost danger has passed.

Sandy soil in Maricopa County dries quickly โ€” mulch Cardoon with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 108ยฐF in Maricopa 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.

Maricopa County receives only 12" of rain annually. Cardoon needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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 Maricopa County, AZ?

Maricopa County is in Zone 9b with an average last frost of January 31. Plan your Cardoon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Maricopa County, AZ?

Maricopa County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is January 31 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

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