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When to Plant Cardoon in Tulsa County, OK

Tulsa County, Oklahoma Zone 7b May

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

Avg. last frost April 7
Avg. first frost October 26
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 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.

Tulsa County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 752 feet, Tulsa County receives approximately 28.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Cardoon during the growing season.

Tulsa County, OK (Zone 7b) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26
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Tulsa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Transplant: Apr 16 🍅 Harvest: Aug 20 – Oct 1
Recommended (50%) ✓ Fits season (20 days to spare)
Transplant: Apr 21 🍅 Harvest: Aug 25 – Oct 6
Safe Start (90%) ✓ Fits season (20 days to spare)
Transplant: May 8 🍅 Harvest: Sep 11 – Oct 23

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 Tulsa County

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

Soil pH

Your soil pH (6.8–7.1) is within Cardoon's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 725 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 3.4" 0.9" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tulsa 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 3,535 GDD Excellent fit

Cardoon Planting Timeline — Tulsa County, OK

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 – May 5
Harvest August 25 Aug 25 – Oct 6

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

202 days in Tulsa County

Growing Tips for Cardoon in Tulsa County

Direct sow Cardoon outdoors after April 07 in Tulsa 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 Tulsa County, OK?

Tulsa County is in Zone 7b with an average last frost of April 7. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tulsa County, OK?

Tulsa County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 26.

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Your Tulsa County Garden Planner — Free

A 24-page printable planner built for Tulsa County (Zone 7b). 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 Tulsa County, OK. 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.