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When to Plant Sunchoke in Clark County, KS

Clark County, Kansas Zone 6b May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Clark County, Kansas this May and put them front and centre. Tackle them in order.

Avg. last frost April 16
Avg. first frost October 22
Soil temp (4") 64°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs

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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.

Clark County, Kansas is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 867 feet, Clark County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Sunchoke during the growing season.

Clark County, KS (Zone 6b) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22
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Clark County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Transplant: Apr 25 🍅 Harvest: Aug 15 – Oct 10
Recommended (50%) ✓ Fits season (7 days to spare)
Transplant: Apr 30 🍅 Harvest: Aug 20 – Oct 15
Safe Start (90%) ✓ Fits season (6 days to spare)
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 Clark County

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

Soil pH

Your soil pH (6.8–7.6) overlaps with Sunchoke's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sunchoke.

Organic Matter

Organic matter is moderate (3.3%). 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
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,624 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 4.3" 2" 2.3" 🚿 Regular watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clark 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 ~2,470 GDD — county provides 3,591 GDD Excellent fit

Sunchoke Planting Timeline — Clark County, KS

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 – May 14
Harvest August 20 Aug 20 – Oct 15

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

189 days in Clark County

Growing Tips for Sunchoke in Clark County

Direct sow Sunchoke outdoors after April 16 in Clark 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.

Clark County receives only 22" of rain annually. Sunchoke needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Clark County, KS?

Clark County is in Zone 6b with an average last frost of April 16. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, KS?

Clark County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 22.

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Your Clark County Garden Planner — Free

A 24-page printable planner built for Clark County (Zone 6b). 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 Clark County, KS. 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.