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When to Plant Crosne in Ada County, ID

Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

Ada County, Idaho is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 4,372 feet, Ada County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Crosne during the growing season. With low rainfall, drip irrigation is essential for growing Crosne successfully. Mulch heavily to conserve soil moisture.

Ada County, ID (Zone 6b) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16

Ada County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 15 🍅 Harvest: Sep 16 – Oct 28
Recommended (50%) ✗ May not fit
Transplant: Apr 23 🍅 Harvest: Sep 24 – Nov 5
Safe Start (90%) ✗ May not fit
Transplant: May 13 🍅 Harvest: Oct 14 – Nov 25

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 Ada County

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

Soil pH

Your soil pH (6.4โ€“7.7) is more alkaline than Crosne prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Ada County is excellent for Crosne โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Crosne.

How to Plant Crosne

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 992 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Crosne

Crosne needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Crosne Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
May 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Jun 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jul 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Oct 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Ada County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Crosne 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.

Crosne needs ~3,062 GDD — county provides 3,080 GDD Good fit

Crosne Planting Timeline โ€” Ada County, ID

Crosne Planting Calendar

Activity When Date Range
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest September 10 Sep 10 โ€“ Oct 22
Fall Sowing August 7 Aug 7 โ€“ Aug 21

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May โ€”
June โ€”
July โ€”
August Fall Sowing
September Harvest
October Harvest
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

150โ€“200 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

176 days in Ada County

Growing Tips for Crosne in Ada County

Direct sow Crosne outdoors after April 23 in Ada County when soil has warmed and frost danger has passed.

Your 176.0-day growing season in Ada County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

Ada County receives only 20" of rain annually. Crosne needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crosne in Ada County, ID?

Ada County is in Zone 6b with an average last frost of April 23. Plan your Crosne planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ada County, ID?

Ada County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ada County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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