When to Plant Cardoon in Jefferson County, OR
Your June gardening checklist
Each item below is timed to Jefferson County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Plant out cardoon
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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.
Jefferson County, Oregon is in USDA Zone 7a. The average last spring frost is June 9 and the first fall frost is September 19, giving you a growing season of approximately 102 days.
At an elevation of 21 feet, Jefferson County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Cardoon to ensure they mature before fall.
Jefferson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.7
Drainage
Well Drained
Cardoon Planting Risk Windows
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 Jefferson County
How your county's soil matches Cardoon's growing requirements.
Soil pH
Your soil pH (5.3–6.7) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Jefferson County is excellent for Cardoon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Cardoon will thrive.
How to Plant Cardoon
Cardoon Water Budget
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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | — | 3.7" | 0" | ❄️ Dormant |
| Mar | — | 3.7" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | — | 1.8" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Jul | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Aug | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | — | 3.2" | 0" | ❄️ Dormant |
| Nov | — | 6.1" | 0" | ❄️ Dormant |
| Dec | — | 5.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Jefferson 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 Planting Timeline — Jefferson County, OR
Cardoon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 23 | Jun 23 – Jul 7 |
| Harvest | October 27 | Oct 27 – Dec 8 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | — |
| September | — |
| October | Harvest |
| November | Harvest |
| December | Harvest |
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 7a
📆 Growing Season
102 days in Jefferson County
Growing Tips for Cardoon in Jefferson County
Direct sow Cardoon outdoors after June 09 in Jefferson County when soil has warmed and frost danger has passed.
Your 102.0-day growing season in Jefferson County is tight for Cardoon (120.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.
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
Check more plant combinations with our Companion Planting Checker →
Cardoon in Other Locations
Frequently Asked Questions
When should I plant Cardoon in Jefferson County, OR?
Jefferson County is in Zone 7a with an average last frost of June 9. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, OR?
Jefferson County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is June 9 and first fall frost is September 19.
Your Jefferson County Garden Planner — Free
A 22-page printable planner built for Jefferson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.