Blog

When to Plant Cardoon in Linn County, OR

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.

Linn County, Oregon is in USDA Zone 8b. The average last spring frost is April 22 and the first fall frost is October 25, giving you a growing season of approximately 186 days.

At an elevation of 259 feet, Linn County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Cardoon to ensure they mature before fall.

Linn County, OR (Zone 8b) Moderate season
186 days
Last Spring Frost April 22
186 growing days
First Fall Frost October 25

Linn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.3

Drainage

Well Drained

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 5.8" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.6" 3.7" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 5.4" 0" ❄️ Dormant
Dec 5.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Linn County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cardoon Planting Timeline — Linn County, OR

Cardoon Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest September 9 Sep 9 – Oct 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

120–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

186 days in Linn County

Growing Tips for Linn County

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 Linn County, OR?

Linn County is in Zone 8b with an average last frost of April 22. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Linn County, OR?

Linn County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 22 and first fall frost is October 25.

🌱

Your Linn County Garden Planner — Free

A 22-page printable planner built for Linn County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.