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When to Plant Sunchoke in Lamar 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.

Lamar County, Texas is in USDA Zone 7b. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.

At an elevation of 95 feet, Lamar County receives approximately 59.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91ยฐF, providing good warmth for Sunchoke during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sunchoke will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunchoke root diseases.

Lamar County, TX (Zone 7b) Long season
245 days
Last Spring Frost March 15
245 growing days
First Fall Frost November 15

Lamar County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Transplant: Mar 21 🍅 Harvest: Jul 11 – Sep 5
Recommended (50%) ✓ Fits season (63 days to spare)
Transplant: Mar 29 🍅 Harvest: Jul 19 – Sep 13
Safe Start (90%) ✓ Fits season (53 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunchoke needs ~2,372 GDD — county provides 4,471 GDD Excellent fit

Sunchoke Planting Timeline โ€” Lamar County, TX

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 โ€“ Apr 12
Harvest July 19 Jul 19 โ€“ Sep 13

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
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

245 days

Growing Tips for Lamar 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 Lamar County, TX?

Lamar County is in Zone 7b with an average last frost of March 15. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lamar County, TX?

Lamar County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 15 and first fall frost is November 15.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lamar 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 Lamar County, TX. Local conditions may vary. Last updated: April 2026.