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When to Plant Sunchoke in Knox County, TX

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

Knox County, Texas is in USDA Zone 7b. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.

At an elevation of 1,847 feet, Knox County receives approximately 51.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Sunchoke during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunchoke root diseases.

Knox County, TX (Zone 7b) Long season
233 days
Last Spring Frost March 24
233 growing days
First Fall Frost November 12

Knox County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Mar 31 🍅 Harvest: Jul 21 – Sep 15
Recommended (50%) ✓ Fits season (51 days to spare)
Transplant: Apr 7 🍅 Harvest: Jul 28 – Sep 22
Safe Start (90%) ✓ Fits season (44 days to spare)
Transplant: Apr 27 🍅 Harvest: Aug 17 – Oct 12

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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 160 gal / 100 sq ft
Sunchoke needs ~2,568 GDD — county provides 4,601 GDD Excellent fit

Sunchoke Planting Timeline โ€” Knox County, TX

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Harvest July 28 Jul 28 โ€“ Sep 22

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

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 7b

Growing Season

233 days

Growing Tips for Knox 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 Knox County, TX?

Knox County is in Zone 7b with an average last frost of March 24. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Knox County, TX?

Knox County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 24 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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 Knox County, TX. Local conditions may vary. Last updated: April 2026.