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When to Plant Sunchoke in Castro 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.

Castro County, Texas is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 3,838 feet, Castro County receives approximately 47.6 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95ยฐF, so Sunchoke may need afternoon shade and extra watering during peak heat. 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.

Castro County, TX (Zone 7a) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24

Castro County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Transplant: Apr 21 🍅 Harvest: Aug 11 – Oct 6
Recommended (50%) ✓ Fits season (11 days to spare)
Transplant: Apr 28 🍅 Harvest: Aug 18 – Oct 13
Safe Start (90%) ✓ Fits season (12 days to spare)
Transplant: May 15 🍅 Harvest: Sep 4 – Oct 30

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
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Sunchoke needs ~2,762 GDD — county provides 4,101 GDD Excellent fit

Sunchoke Planting Timeline โ€” Castro County, TX

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Harvest August 18 Aug 18 โ€“ Oct 13

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

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 7a

Growing Season

193 days

Growing Tips for Castro 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 Castro County, TX?

Castro County is in Zone 7a with an average last frost of April 14. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Castro County, TX?

Castro County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.

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Plan Your Garden with Confidence

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