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When to Plant Crosne in Franklin County, ME

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.

Franklin County, Maine is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.

At an elevation of 244 feet, Franklin County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Crosne to ensure they mature before fall.

Franklin County, ME (Zone 4a) Short season
137 days
Last Spring Frost May 14
137 growing days
First Fall Frost September 28

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 11 🍅 Harvest: Oct 12 – Oct 5
Recommended (50%) ✗ May not fit
Transplant: May 14 🍅 Harvest: Oct 15 – Oct 8
Safe Start (90%) ✗ May not fit
Transplant: May 31 🍅 Harvest: Nov 1 – Oct 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 Franklin County

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

Soil pH

Your soil pH (5.2โ€“6.6) is more acidic than Crosne prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 2.6" 0" โ„๏ธ Dormant
Mar โ€” 3.9" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jul 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Aug 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct โ€” 3.4" 0" โ„๏ธ Dormant
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 3.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Franklin 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 ~1,750 GDD — county provides 1,370 GDD May not mature

Crosne Planting Timeline โ€” Franklin County, ME

Crosne Planting Calendar

Activity When Date Range
Direct Sow May 7 May 7 โ€“ May 28
Harvest October 8 Oct 8 โ€“ Oct 1
Fall Sowing July 6 Jul 6 โ€“ Jul 20

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

150โ€“200 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

137 days in Franklin County

Growing Tips for Crosne in Franklin County

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

Your 137.0-day growing season in Franklin County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Franklin County, ME?

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

What planting zone is Franklin County, ME?

Franklin County, Maine is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Franklin County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Franklin County, ME. Local conditions may vary. Last updated: April 2026.