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When to Plant Cardoon in Hardin County, TN

Hardin County, Tennessee Zone 7b May

May in the garden — Hardin County, Tennessee

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

Avg. last frost March 31
Avg. first frost October 28
Soil temp (4") 62°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.

Hardin County, Tennessee is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 28, giving you a growing season of approximately 211 days.

At an elevation of 3,095 feet, Hardin County receives approximately 53.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Cardoon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cardoon root diseases.

Hardin County, TN (Zone 7b) Long season
211 days
Last Spring Frost March 31
211 growing days
First Fall Frost October 28
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Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Transplant: Apr 7 🍅 Harvest: Aug 11 – Sep 22
Recommended (50%) ✓ Fits season (29 days to spare)
Transplant: Apr 14 🍅 Harvest: Aug 18 – Sep 29
Safe Start (90%) ✓ Fits season (29 days to spare)
Transplant: Apr 30 🍅 Harvest: Sep 3 – Oct 15

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 Hardin County

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

Soil pH

Your soil pH (5.4–6.7) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.2" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 4.3" 5.2" 0" ✅ Rainfall sufficient
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Hardin 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 ~2,666 GDD — county provides 4,167 GDD Excellent fit

Cardoon Planting Timeline — Hardin County, TN

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors April 14 Apr 14 – Apr 28
Harvest August 18 Aug 18 – Sep 29

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 · Natural rainfall sufficient

📅 Days to Maturity

120–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in Hardin County

Growing Tips for Cardoon in Hardin County

Direct sow Cardoon outdoors after March 31 in Hardin 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 Hardin County, TN?

Hardin County is in Zone 7b with an average last frost of March 31. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, TN?

Hardin County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 28.

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Your Hardin County Garden Planner — Free

A 24-page printable planner built for Hardin 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 Hardin 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.