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When to plant Sunchoke in Union County County,

In Union County County, Sunchoke is a spring-only crop. Plant March 15–March 29 once soil hits 50°F.

When to Plant Sunchoke in Union County, FL

Union County, Florida Zone 9a June

June to-do list for Union County, Florida

Here's what deserves your attention in Union County, Florida this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 1
Avg. first frost November 27
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
July prep starts now
  • First harvests: sunchoke

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

Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.

At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Sunchoke may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.

Union County, FL (Zone 9a) Year-round
271 days
Last Spring Frost March 1
271 growing days
First Fall Frost November 27
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Union County Soil Profile

Soil Type

Sand

Soil pH

5.2-6

Drainage

Well Drained

Sunchoke Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Transplant: Feb 28 🍅 Harvest: Jun 20 – Aug 15
Recommended (50%) ✓ Fits season (89 days to spare)
Transplant: Mar 15 🍅 Harvest: Jul 5 – Aug 30
Safe Start (90%) ✓ Fits season (87 days to spare)
Transplant: Apr 9 🍅 Harvest: Jul 30 – Sep 24

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 Union County

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

Soil pH

Your soil pH (5.2–6.0) is more acidic than Sunchoke prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Union County warms quickly in spring but drains fast. Sunchoke will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Sunchoke.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Sunchoke.

How to Plant Sunchoke

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Sunchoke 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 870 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 3.1" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 8.1" 0" ✅ Rainfall sufficient
Jul 4.3" 10" 0" ✅ Rainfall sufficient
Aug 4.3" 9" 0" ✅ Rainfall sufficient
Sep 4.3" 7.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~2,860 GDD — county provides 5,962 GDD Excellent fit

Sunchoke Planting Timeline — Union County, FL

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors March 15 Mar 15 – Mar 29
Harvest July 5 Jul 5 – Aug 30

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April
May
June
July Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

271 days in Union County

Growing Tips for Sunchoke in Union County

Direct sow Sunchoke outdoors after March 01 in Union County when soil has warmed and frost danger has passed.

Sandy soil in Union County dries quickly — mulch Sunchoke with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Union 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 Union County, FL?

Union County is in Zone 9a with an average last frost of March 1. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, FL?

Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.

When should I plant Sunchoke in Union County, ?

In Union County, , plant Sunchoke after the last frost (around March 1) and before the first frost (around November 27). Best results when soil holds above 50°F.

What growing zone is Union County, for Sunchoke?

Union County sits in USDA Zone 9a. Sunchoke grows reliably in zones 3a through 9b, so it's a good fit here.

Can Sunchoke grow in Union County's climate?

Yes — Sunchoke grows well in Union County's temperate climate. Union County averages a 271-day frost-free season, with last frost around March 1 and first frost around November 27.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Union County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.