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When to Plant Sunchoke in Barnstable County, MA

Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Barnstable County, Massachusetts is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 518 feet, Barnstable County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Sunchoke during the growing season.

Barnstable County, MA (Zone 7a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Barnstable County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Transplant: Apr 24 🍅 Harvest: Aug 14 – Oct 9
Recommended (50%) ✓ Fits season (7 days to spare)
Transplant: May 2 🍅 Harvest: Aug 22 – Oct 17
Safe Start (90%) ✓ Fits season (1 days to spare)
Transplant: May 25 🍅 Harvest: Sep 14 – Nov 9

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 Barnstable County

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

Soil pH

Your soil pH (5.0โ€“6.4) is more acidic than Sunchoke prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Sunchoke.

How to Plant Sunchoke

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sunchoke

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

Month Sunchoke Needs Rainfall You Supplement Action
Jan โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 3.1" 0" โ„๏ธ Dormant
Mar โ€” 4.2" 0" โ„๏ธ Dormant
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 4.7" 0" โœ… Rainfall sufficient
Jun 4.3" 4.7" 0" โœ… Rainfall sufficient
Jul 4.3" 4.9" 0" โœ… Rainfall sufficient
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Oct 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 3" 0" โ„๏ธ Dormant

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

Sunchoke 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.

Sunchoke needs ~2,372 GDD — county provides 3,449 GDD Excellent fit

Sunchoke Planting Timeline โ€” Barnstable County, MA

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 2 May 2 โ€“ May 16
Harvest August 22 Aug 22 โ€“ Oct 17

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July โ€”
August Harvest
September Harvest
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

110โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

189 days in Barnstable County

Growing Tips for Sunchoke in Barnstable County

Direct sow Sunchoke outdoors after April 18 in Barnstable County when soil has warmed and frost danger has passed.

Common pests for Sunchoke in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunchoke in Barnstable County, MA?

Barnstable County is in Zone 7a with an average last frost of April 18. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Barnstable County, MA?

Barnstable County, Massachusetts is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Barnstable County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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