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When to Plant Sunchoke in Jackson 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.

Jackson County, Texas is in USDA Zone 9a. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.

At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, so Sunchoke may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunchoke root diseases.

Jackson County, TX (Zone 9a) Year-round
287 days
Last Spring Frost February 21
287 growing days
First Fall Frost December 5

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Transplant: Feb 22 🍅 Harvest: Jun 14 – Aug 9
Recommended (50%) ✓ Fits season (105 days to spare)
Transplant: Mar 7 🍅 Harvest: Jun 27 – Aug 22
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: Mar 28 🍅 Harvest: Jul 18 – Sep 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.

Soil Compatibility in Jackson County

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

Soil pH

Your soil pH (6.5โ€“7.2) is within Sunchoke's preferred range (6.0โ€“7.5).

Soil Texture

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

Drainage

Drainage is adequate for Sunchoke.

Organic Matter

Organic matter is moderate (2.0%). 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
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 929 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€” 1.7" 0" โ„๏ธ Dormant
Feb 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Mar 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Apr 4.3" 6.5" 0" โœ… Rainfall sufficient
May 4.3" 9" 0" โœ… Rainfall sufficient
Jun 4.3" 10.4" 0" โœ… Rainfall sufficient
Jul 4.3" 7.9" 0" โœ… Rainfall sufficient
Aug 4.3" 8" 0" โœ… Rainfall sufficient
Sep 4.3" 6" 0" โœ… Rainfall sufficient
Oct 4.3" 4.8" 0" โœ… Rainfall sufficient
Nov 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Dec 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Jackson 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 ~3,542 GDD — county provides 7,848 GDD Excellent fit

Sunchoke Planting Timeline โ€” Jackson County, TX

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors March 7 Mar 7 โ€“ Mar 21
Harvest June 27 Jun 27 โ€“ Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

110โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

287 days in Jackson County

Growing Tips for Sunchoke in Jackson County

Direct sow Sunchoke outdoors after February 21 in Jackson County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in Jackson County, provide afternoon shade for Sunchoke and water deeply in the morning.

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 Jackson County, TX?

Jackson County is in Zone 9a with an average last frost of February 21. Plan your Sunchoke planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, TX?

Jackson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 21 and first fall frost is December 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jackson County gardeners in Zone 9a 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 Jackson County, TX. Local conditions may vary. Last updated: April 2026.