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When to plant Sunchoke in Cook County, MN

In Cook County, Sunchoke is a single-season spring crop — there's no second fall window. Plant June 3–June 17 for an 110–150-day harvest, finishing well before the September 29 first frost.

When to Plant Sunchoke in Cook County, MN

Cook County, Minnesota Zone 3b June

Top priorities for Cook County, Minnesota gardeners in June

We've pulled the most time-sensitive tasks for Cook County, Minnesota this June and put them front and centre. Tackle them in order.

Avg. last frost May 20
Avg. first frost September 29
Soil temp (4") 63°F
Watering Low
Pest pressure Moderate
Daylight 15.8 hrs
  1. Transplant sunchoke outside

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

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

Cook County, Minnesota is in USDA Zone 3b. The average last spring frost is May 20 and the first fall frost is September 29, giving you a growing season of approximately 132 days.

At an elevation of 1,068 feet, Cook County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Sunchoke to ensure they mature before fall.

Cook County, MN (Zone 3b) Short season
132 days
Last Spring Frost May 20
132 growing days
First Fall Frost September 29

Cook County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Sunchoke Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 29 🍅 Harvest: Sep 18 – Oct 2
Recommended (50%) ✗ May not fit
Transplant: Jun 3 🍅 Harvest: Sep 23 – Oct 7
Safe Start (90%) ✗ May not fit
Transplant: Jun 14 🍅 Harvest: Oct 4 – Oct 18

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 Cook County

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

Soil pH

Your soil pH (6.1–7.1) is within Sunchoke's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — Sunchoke will thrive.

How to Plant Sunchoke

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

Sunchoke Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 2.7" 0" ❄️ Dormant
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Sunchoke needs ~1,300 GDD — county provides 1,320 GDD Good fit

Sunchoke Planting Timeline — Cook County, MN

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors June 3 Jun 3 – Jun 17
Harvest September 23 Sep 23 – Oct 7

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 3b

📆 Growing Season

132 days in Cook County

Growing Tips for Sunchoke in Cook County

Direct sow Sunchoke outdoors after May 20 in Cook County when soil has warmed and frost danger has passed.

Your 132.0-day growing season in Cook County is tight for Sunchoke (110.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Cook County, MN?

Cook County is in Zone 3b with an average last frost of May 20. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cook County, MN?

Cook County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 20 and first fall frost is September 29.

When should I plant Sunchoke in Cook County, MN?

In Cook County, MN, plant Sunchoke after the last frost (around May 20) and before the first frost (around September 29). Best results when soil holds above 50°F.

What growing zone is Cook County, MN for Sunchoke?

Cook County sits in USDA Zone 3b. Sunchoke grows reliably in zones 3a through 9b, so it's a good fit here.

Can Sunchoke grow in Cook County's climate?

Yes — Sunchoke grows well in Cook County's temperate climate. Cook County averages a 132-day frost-free season, with last frost around May 20 and first frost around September 29.

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Your Cook County Garden Planner — Free

A 22-page printable planner built for Cook County (Zone 3b). 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 Cook County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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