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When to plant Jicama in Johnson County County,

Johnson County County gardeners should plant Jicama between April 14 and May 5 in spring. With Johnson County County's Zone 7a climate (last frost April 7), Jicama needs 180 days to mature — plant by April 24 for a full harvest.

When to Plant Jicama in Johnson County, IL

Jicama is a tropical legume grown for its crisp, sweet, starchy root. It requires a very long, warm growing season but produces a refreshing, water chestnut-like tuber.

Johnson County, Illinois is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 21, giving you a growing season of approximately 197 days.

At an elevation of 1,006 feet, Johnson County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Jicama during the growing season.

Johnson County, IL (Zone 7a) Moderate season
197 days
Last Spring Frost April 7
197 growing days
First Fall Frost October 21
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Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Monthly Watering Guide for Jicama

Jicama needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Jicama Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Johnson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Jicama Planting Timeline — Johnson County, IL

Jicama Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 14 Apr 14 – May 5
Harvest August 25 Aug 25 – Nov 3

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

197 days in Johnson County

Growing Tips for Johnson County

Start seeds indoors 8-10 weeks before last frost. Pinch off flowers to direct energy to root development. Harvest before first frost when roots are 3-6 inches across.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Jicama in Johnson County, IL?

Johnson County is in Zone 7a with an average last frost of April 7. Plan your Jicama planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, IL?

Johnson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 21.

When should I plant Jicama in Johnson County County, ?

In Johnson County County, , plant Jicama after the last frost (around April 7) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Johnson County County, for Jicama?

Johnson County County sits in USDA Zone 7a. Jicama grows reliably in zones 7a through 11b, so it's a good fit here.

Can Jicama grow in Johnson County County's climate?

Yes — Jicama grows well in Johnson County County's temperate climate. Johnson County County averages a 197-day frost-free season, with last frost around April 7 and first frost around October 21.

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Your Johnson County Garden Planner — Free

A 22-page printable planner built for Johnson County (Zone 7a). 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 Johnson County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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