Blog

When to Plant Sunchoke in Dallas County, AR

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

Dallas County, Arkansas is in USDA Zone 7b. The average last spring frost is March 20 and the first fall frost is November 11, giving you a growing season of approximately 236 days.

At an elevation of 305 feet, Dallas County receives approximately 45.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Sunchoke during the growing season.

Dallas County, AR (Zone 7b) Long season
236 days
Last Spring Frost March 20
236 growing days
First Fall Frost November 11

Dallas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Transplant: Mar 27 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (54 days to spare)
Transplant: Apr 3 🍅 Harvest: Jul 24 – Sep 18
Safe Start (90%) ✓ Fits season (52 days to spare)
Transplant: Apr 23 🍅 Harvest: Aug 13 – Oct 8

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 Dallas County

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

Soil pH

Your soil pH (5.6โ€“6.8) overlaps with Sunchoke's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 396 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€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 3.5" 0" โ„๏ธ Dormant
Mar 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Apr 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 4.3" 0" โœ… Rainfall sufficient
Jul 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Aug 4.3" 4.6" 0" โœ… Rainfall sufficient
Sep 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Oct 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Nov 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Dec โ€” 3.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Dallas 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 ~2,275 GDD — county provides 4,130 GDD Excellent fit

Sunchoke Planting Timeline โ€” Dallas County, AR

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 3 Apr 3 โ€“ Apr 17
Harvest July 24 Jul 24 โ€“ Sep 18

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 โ€”
June โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

110โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

236 days in Dallas County

Growing Tips for Sunchoke in Dallas County

Direct sow Sunchoke outdoors after March 20 in Dallas 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 Dallas County, AR?

Dallas County is in Zone 7b with an average last frost of March 20. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dallas County, AR?

Dallas County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 20 and first fall frost is November 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dallas County gardeners in Zone 7b 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 Dallas County, AR. Local conditions may vary. Last updated: April 2026.