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When to plant Sunchoke in Bath, IL

Bath's 182-day season only supports one Sunchoke planting per year. Sow between April 29 and May 13 for the best chance at full maturity before October 14.

When to Plant Sunchoke in Bath, IL

Mason County, Illinois Zone 6a August

August in Mason County, Illinois — your action list

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

Avg. last frost April 15
Avg. first frost October 14
Soil temp (4") 79°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for sunchoke

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong September, finish these tasks
  • First harvests: sunchoke

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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.

Bath, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 14, giving you a growing season of approximately 182 days.

At an elevation of 768 feet, Mason County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sunchoke during the growing season.

Bath, IL (Zone 6a) Moderate season
182 days
Last Spring Frost April 15
182 growing days
First Fall Frost October 14

Bath Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Sunchoke Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 26 🍅 Harvest: Aug 16 – Oct 11
Recommended (50%) ✓ Fits season (0 days to spare)
Transplant: Apr 29 🍅 Harvest: Aug 19 – Oct 14
Safe Start (90%) ✗ May not fit
Transplant: May 14 🍅 Harvest: Sep 3 – Oct 29

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 Bath

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

Soil pH

Your soil pH (6.1–6.9) is within Sunchoke's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — 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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 580 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 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 4.3" 2.2" 2.1" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Mason 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 ~1,885 GDD — county provides 2,639 GDD Excellent fit

Sunchoke Planting Timeline — Bath, IL

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 29 Apr 29 – May 13
Harvest August 19 Aug 19 – Oct 14

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

182 days in Mason County

Growing Tips for Sunchoke in Bath

Direct sow Sunchoke outdoors after April 15 in Mason 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 →

When should I plant Sunchoke in Bath, IL?

In Bath, IL, plant Sunchoke after the last frost (around April 15) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Bath, IL for Sunchoke?

Bath sits in USDA Zone 6a. Sunchoke grows reliably in zones 3a through 9b, so it's a good fit here.

Can Sunchoke grow in Bath's climate?

Yes — Sunchoke grows well in Bath's temperate climate. Bath averages a 182-day frost-free season, with last frost around April 15 and first frost around October 14.

🌱

Your Mason County Garden Planner — Free

A 22-page printable planner built for Mason County (Zone 6a). 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 Mason County, IL. Local conditions may vary. Last updated: August 2026.