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When to Plant Sunchoke in Box Elder County, UT

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

Box Elder County, Utah is in USDA Zone 6a. The average last spring frost is May 22 and the first fall frost is October 3, giving you a growing season of approximately 134 days.

At an elevation of 4,039 feet, Box Elder County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Sunchoke during the growing season.

Box Elder County, UT (Zone 6a) Short season
134 days
Last Spring Frost May 22
134 growing days
First Fall Frost October 3

Box Elder County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 26 🍅 Harvest: Sep 15 – Nov 10
Recommended (50%) ✗ May not fit
Transplant: Jun 5 🍅 Harvest: Sep 25 – Nov 20
Safe Start (90%) ✗ May not fit
Transplant: Jun 24 🍅 Harvest: Oct 14 – Dec 9

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 332 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Sunchoke needs ~1,982 GDD — county provides 2,043 GDD Good fit

Sunchoke Planting Timeline โ€” Box Elder County, UT

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors June 5 Jun 5 โ€“ Jun 19
Harvest September 25 Sep 25 โ€“ Nov 20

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

110โ€“150 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

134 days

Growing Tips for Box Elder County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunchoke in Box Elder County, UT?

Box Elder County is in Zone 6a with an average last frost of May 22. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Box Elder County, UT?

Box Elder County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 22 and first fall frost is October 3.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Box Elder County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Box Elder County, UT. Local conditions may vary. Last updated: April 2026.