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When to Plant Sunchoke in Ray County, MO

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

Ray County, Missouri is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 25, giving you a growing season of approximately 193 days.

At an elevation of 747 feet, Ray County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92ยฐF, providing good warmth for Sunchoke during the growing season.

Ray County, MO (Zone 6a) Moderate season
193 days
Last Spring Frost April 15
193 growing days
First Fall Frost October 25

Ray County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Transplant: Apr 20 🍅 Harvest: Aug 10 – Oct 5
Recommended (50%) ✓ Fits season (11 days to spare)
Transplant: Apr 29 🍅 Harvest: Aug 19 – Oct 14
Safe Start (90%) ✓ Fits season (8 days to spare)
Transplant: May 13 🍅 Harvest: Sep 2 – Oct 28

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 Ray County

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

Soil pH

Your soil pH (5.6โ€“6.6) overlaps with Sunchoke's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 590 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jul 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Aug 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Sep 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Oct 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Ray 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 ~2,470 GDD — county provides 3,667 GDD Excellent fit

Sunchoke Planting Timeline โ€” Ray County, MO

Sunchoke Planting Calendar

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

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
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 1-2 times/week

๐Ÿ“… Days to Maturity

110โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

193 days in Ray County

Growing Tips for Sunchoke in Ray County

Direct sow Sunchoke outdoors after April 15 in Ray 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 Ray County, MO?

Ray County is in Zone 6a with an average last frost of April 15. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ray County, MO?

Ray County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ray County gardeners in Zone 6a 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 Ray County, MO. Local conditions may vary. Last updated: April 2026.