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When to Plant Crosne in Blaine County, MT

Blaine County, Montana Zone 4a May

Your May gardening checklist

Each item below is timed to Blaine County, Montana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 14
Avg. first frost September 24
Soil temp (4") 31°F
Watering Moderate
Pest pressure Low
Daylight 15 hrs
  1. Outdoor sowing time: crosne

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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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.

Blaine County, Montana is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 24, giving you a growing season of approximately 133 days.

At an elevation of 7,816 feet, Blaine County receives approximately 23.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Crosne to ensure they mature before fall.

Blaine County, MT (Zone 4a) Short season
133 days
Last Spring Frost May 14
133 growing days
First Fall Frost September 24

Blaine 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: May 10 🍅 Harvest: Oct 11 – Oct 4
Recommended (50%) ✗ May not fit
Transplant: May 14 🍅 Harvest: Oct 15 – Oct 8
Safe Start (90%) ✗ May not fit
Transplant: May 27 🍅 Harvest: Oct 28 – Oct 21

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 Blaine County

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

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Crosne.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Crosne.

How to Plant Crosne

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 775 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 2.3" 2" 💧 Light watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Blaine 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 ~2,012 GDD — county provides 1,529 GDD May not mature

Crosne Planting Timeline — Blaine County, MT

Crosne Planting Calendar

Activity When Date Range
Direct Sow May 7 May 7 – May 28
Harvest October 8 Oct 8 – Oct 1
Fall Sowing July 2 Jul 2 – Jul 16

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

Month-by-Month Timeline

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

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_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

133 days in Blaine County

Growing Tips for Crosne in Blaine County

Direct sow Crosne outdoors after May 14 in Blaine County when soil has warmed and frost danger has passed.

Your 133.0-day growing season in Blaine County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

Blaine County receives only 24" 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 Blaine County, MT?

Blaine County is in Zone 4a with an average last frost of May 14. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.

What planting zone is Blaine County, MT?

Blaine County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 24.

🌱

Your Blaine County Garden Planner — Free

A 24-page printable planner built for Blaine County (Zone 4a). 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 Blaine County, MT. 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.