When to Plant Cardoon in Franklin County, WA
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.
Franklin County, Washington is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 23, giving you a growing season of approximately 193 days.
At an elevation of 1,556 feet, Franklin County receives approximately 15.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Cardoon during the growing season. With low rainfall, drip irrigation is essential for growing Cardoon successfully. Mulch heavily to conserve soil moisture.
Franklin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.6
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.
Plant Water Budget
Cardoon Planting Timeline — Franklin County, WA
Cardoon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Harvest | August 31 | Aug 31 – Oct 12 |
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
Moderate — regular watering
Days to Maturity
120–150 days
Soil pH
6 – 7.5
USDA Zone
Zone 7a
Growing Season
193 days
Growing Tips for Franklin 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
Level Up Your Garden
Cardoon in Other Locations
Frequently Asked Questions
When should I plant Cardoon in Franklin County, WA?
Franklin County is in Zone 7a with an average last frost of April 13. Plan your Cardoon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Franklin County, WA?
Franklin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 23.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Franklin County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.
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