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When to Plant Cardoon in Shelby County, TN

Shelby County, Tennessee Zone 8a May

May to-do list for Shelby County, Tennessee

Each item below is timed to Shelby County, Tennessee's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 21
Avg. first frost November 5
Soil temp (4") 60°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 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.

Shelby County, Tennessee is in USDA Zone 8a. The average last spring frost is March 21 and the first fall frost is November 5, giving you a growing season of approximately 229 days.

At an elevation of 3,465 feet, Shelby County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cardoon during the growing season.

Shelby County, TN (Zone 8a) Long season
229 days
Last Spring Frost March 21
229 growing days
First Fall Frost November 5
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Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Transplant: Mar 28 🍅 Harvest: Aug 1 – Sep 12
Recommended (50%) ✓ Fits season (47 days to spare)
Transplant: Apr 4 🍅 Harvest: Aug 8 – Sep 19
Safe Start (90%) ✓ Fits season (47 days to spare)
Transplant: Apr 24 🍅 Harvest: Aug 28 – Oct 9

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 Shelby County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). 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
0.2″/week
Watering frequency Only during dry spells
Season total 330 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 3.3" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.3" 4.2" 0.1" 💧 Light watering
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 3.5" 0.8" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Shelby 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 ~2,261 GDD — county provides 3,835 GDD Excellent fit

Cardoon Planting Timeline — Shelby County, TN

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors April 4 Apr 4 – Apr 18
Harvest August 8 Aug 8 – Sep 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June
July
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 8a

📆 Growing Season

229 days in Shelby County

Growing Tips for Cardoon in Shelby County

Direct sow Cardoon outdoors after March 21 in Shelby 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 Shelby County, TN?

Shelby County is in Zone 8a with an average last frost of March 21. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, TN?

Shelby County, Tennessee is in USDA Hardiness Zone 8a. The average last spring frost is March 21 and first fall frost is November 5.

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Your Shelby County Garden Planner — Free

A 24-page printable planner built for Shelby County (Zone 8a). 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 Shelby County, TN. 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.