Blog

When to Plant Cardoon in Putnam County, FL

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.

Putnam County, Florida is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.

At an elevation of 278 feet, Putnam County receives approximately 57.5 inches of rainfall annually with predominantly sand soil. Summer highs average 95ยฐF, 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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cardoon root diseases.

Putnam County, FL (Zone 9a) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2

Putnam County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (122 days to spare)
Transplant: Feb 8 🍅 Harvest: Jun 14 – Jul 26
Recommended (50%) ✓ Fits season (114 days to spare)
Transplant: Feb 23 🍅 Harvest: Jun 29 – Aug 10
Safe Start (90%) ✓ Fits season (115 days to spare)
Transplant: Mar 18 🍅 Harvest: Jul 22 – Sep 2

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 Putnam County

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

Soil pH

Your soil pH (4.9โ€“6.2) is more acidic than Cardoon prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Cardoon.

Organic Matter

Organic matter is low (1.4%). 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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,544 gal / 100 sq ft
Drought risk

Water stress score is 6/10 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 โ€” 2.4" 0" โ„๏ธ Dormant
Feb 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Mar 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Apr 4.3" 2.3" 2" ๐Ÿ’ง Light watering
May 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Jun 4.3" 7.9" 0" โœ… Rainfall sufficient
Jul 4.3" 9.4" 0" โœ… Rainfall sufficient
Aug 4.3" 8.7" 0" โœ… Rainfall sufficient
Sep 4.3" 7.4" 0" โœ… Rainfall sufficient
Oct 4.3" 5.3" 0" โœ… Rainfall sufficient
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Putnam 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 ~2,869 GDD — county provides 6,311 GDD Excellent fit

Cardoon Planting Timeline โ€” Putnam County, FL

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors February 23 Feb 23 โ€“ Mar 9
Harvest June 29 Jun 29 โ€“ Aug 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March Transplant Outdoors
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 1-2 times/week

๐Ÿ“… Days to Maturity

120โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

296 days in Putnam County

Growing Tips for Cardoon in Putnam County

Direct sow Cardoon outdoors after February 09 in Putnam County when soil has warmed and frost danger has passed.

Sandy soil in Putnam 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.

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 Putnam County, FL?

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

What planting zone is Putnam County, FL?

Putnam County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Putnam County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Putnam County, FL. Local conditions may vary. Last updated: April 2026.