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When to Plant Crosne in Spokane County, WA

Spokane County, Washington Zone 6b May

Spokane County, Washington gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Spokane County, Washington.

Avg. last frost May 11
Avg. first frost September 27
Soil temp (4") 61°F
Watering High
Pest pressure Low
Daylight 14.9 hrs

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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.

Spokane County, Washington is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 27, giving you a growing season of approximately 139 days.

At an elevation of 1,645 feet, Spokane County receives approximately 20.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Crosne during the growing season.

Spokane County, WA (Zone 6b) Short season
139 days
Last Spring Frost May 11
139 growing days
First Fall Frost September 27
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Spokane County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 30 🍅 Harvest: Oct 1 – Nov 12
Recommended (50%) ✗ May not fit
Transplant: May 11 🍅 Harvest: Oct 12 – Nov 23
Safe Start (90%) ✗ May not fit
Transplant: Jun 12 🍅 Harvest: Nov 13 – Dec 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 Spokane County

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

Soil pH

Your soil pH (5.5–6.2) is more acidic than Crosne prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Spokane County is excellent for Crosne — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.4%) — Crosne will thrive.

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
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 475 gal / 100 sq ft

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 3.1" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.7" 3.6" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 3.3" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Spokane County). Supplement amounts are based on average rainfall — 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" — 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.

Crosne needs ~3,194 GDD — county provides 2,536 GDD May not mature

Crosne Planting Timeline — Spokane County, WA

Crosne Planting Calendar

Activity When Date Range
Direct Sow April 27 Apr 27 – May 18
Harvest September 28 Sep 28 – Nov 9
Fall Sowing July 19 Jul 19 – Aug 2

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June
July Fall Sowing
August Fall Sowing
September Harvest
October Harvest
November Harvest
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

150–200 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

139 days in Spokane County

Growing Tips for Crosne in Spokane County

Direct sow Crosne outdoors after May 11 in Spokane County when soil has warmed and frost danger has passed.

Your 139.0-day growing season in Spokane County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

Spokane County receives only 20" of rain annually. Crosne needs consistent moisture — 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 Spokane County, WA?

Spokane County is in Zone 6b with an average last frost of May 11. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.

What planting zone is Spokane County, WA?

Spokane County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 27.

🌱

Your Spokane County Garden Planner — Free

A 24-page printable planner built for Spokane County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Spokane County, WA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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