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When to Plant Turnip in Kendall County, IL

Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Kendall County, Illinois is in USDA Zone 5a. The average last spring frost is April 20 and the first fall frost is October 17, giving you a growing season of approximately 180 days.

At an elevation of 708 feet, Kendall County receives approximately 38.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Turnip during the growing season.

Kendall County, IL (Zone 5a) Moderate season
180 days
Last Spring Frost April 20
180 growing days
First Fall Frost October 17

Kendall County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Transplant: Apr 14 🍅 Harvest: May 26 – Jun 30
Recommended (50%) ✓ Fits season (103 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 1 – Jul 6
Safe Start (90%) ✓ Fits season (98 days to spare)
Transplant: May 9 🍅 Harvest: Jun 20 – Jul 25

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 Kendall County

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

Soil pH

Your soil pH (6.1โ€“6.8) is within Turnip's preferred range (6.0โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) โ€” Turnip will thrive.

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

5
successive plantings in your 180-day season

Sow every 4.6 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 174 gal / 100 sq ft

Monthly Watering Guide for Turnip

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

Month Turnip Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 3" 0" โ„๏ธ Dormant
Apr 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 5.3" 0" โœ… Rainfall sufficient
Jul 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Aug 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Kendall County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Turnip 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.

Turnip needs ~688 GDD — county provides 2,475 GDD Excellent fit

Turnip Planting Timeline โ€” Kendall County, IL

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 6 Apr 6 โ€“ Apr 27
Harvest May 18 May 18 โ€“ Jun 22
Fall Sowing August 8 Aug 8 โ€“ Aug 22

Plant 0.5" deep ยท 4" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Harvest
June Harvest
July โ€”
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

180 days in Kendall County

Growing Tips for Turnip in Kendall County

Direct sow Turnip outdoors after April 20 in Kendall County when soil has warmed and frost danger has passed.

Your generous 180.0-day season in Kendall County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.

Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in Kendall County, IL?

Kendall County is in Zone 5a with an average last frost of April 20. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kendall County, IL?

Kendall County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 20 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kendall County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Kendall County, IL. Local conditions may vary. Last updated: April 2026.