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When to plant Turnip in Cass County, IA

Plant Turnip in Cass County from April 11 to May 2 in spring. Cass County sits in USDA Zone 5b, with last frost around April 25 and first frost on October 9. A second sowing from July 31 to August 14 extends the harvest into fall.

When to Plant Turnip in Cass County, IA

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.

Cass County, Iowa is in USDA Zone 5b. The average last spring frost is April 25 and the first fall frost is October 9, giving you a growing season of approximately 167 days.

At an elevation of 1,043 feet, Cass County receives approximately 31.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Turnip during the growing season.

Cass County, IA (Zone 5b) Moderate season
167 days
Last Spring Frost April 25
167 growing days
First Fall Frost October 9

Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 3.4" 0.9" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Turnip Planting Timeline — Cass County, IA

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 11 Apr 11 – May 2
Harvest May 23 May 23 – Jun 27
Fall Sowing July 31 Jul 31 – Aug 14

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

167 days in Cass County

Growing Tips for Cass County

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 Cass County, IA?

Cass County is in Zone 5b with an average last frost of April 25. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, IA?

Cass County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 25 and first fall frost is October 9.

When should I plant Turnip in Cass County, IA?

In Cass County, IA, plant Turnip after the last frost (around April 25) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Cass County, IA for Turnip?

Cass County sits in USDA Zone 5b. Turnip grows reliably in zones 2a through 10b, so it's a good fit here.

Can Turnip grow in Cass County's climate?

Yes — Turnip grows well in Cass County's temperate climate. Cass County averages a 167-day frost-free season, with last frost around April 25 and first frost around October 9.

🌱

Your Cass County Garden Planner — Free

A 22-page printable planner built for Cass County (Zone 5b). 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 Cass County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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