When to Plant Cardoon in Douglas 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.
Douglas County, Oregon is in USDA Zone 8a. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.
At an elevation of 377 feet, Douglas County receives approximately 52.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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.
Douglas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.4
Drainage
Well Drained
Plant 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 Douglas County
How your county's soil matches Cardoon's growing requirements.
Soil pH
Your soil pH (5.8–6.4) overlaps with Cardoon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Douglas County is excellent for Cardoon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.4%) — Cardoon will thrive.
How to Plant Cardoon
Plant 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 | — | 8.6" | 0" | ❄️ Dormant |
| Feb | — | 6.2" | 0" | ❄️ Dormant |
| Mar | — | 4.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Jun | 4.3" | 2.3" | 2" | 💧 Light watering |
| Jul | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Aug | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Sep | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Oct | 4.3" | 4" | 0.3" | 💧 Light watering |
| Nov | 4.3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Douglas 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 — Douglas County, OR
Cardoon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Harvest | August 22 | Aug 22 – Oct 3 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
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 8a
📆 Growing Season
215 days in Douglas County
Growing Tips for Cardoon in Douglas County
Direct sow Cardoon outdoors after April 04 in Douglas 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
Check more plant combinations with our Companion Planting Checker →
Cardoon in Other Locations
Frequently Asked Questions
When should I plant Cardoon in Douglas County, OR?
Douglas County is in Zone 8a with an average last frost of April 4. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Douglas County, OR?
Douglas County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 4 and first fall frost is November 5.
Plan Your Garden with Confidence
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