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When to Plant Kale in Floyd County, IA

Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.

Floyd County, Iowa is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 714 feet, Floyd County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Kale to ensure they mature before fall.

Floyd County, IA (Zone 4b) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Floyd County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 21
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 4

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 Floyd County

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

Soil pH

Your soil pH (5.9โ€“6.8) overlaps with Kale's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Kale.

How to Plant Kale

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Kale

3
successive plantings in your 159-day season

Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Kale

Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Kale Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 3.5" 3.6" 0" โœ… Rainfall sufficient
Jun 3.5" 3.8" 0" โœ… Rainfall sufficient
Jul 3.5" 3.9" 0" โœ… Rainfall sufficient
Aug 3.5" 3.4" 0.1" ๐Ÿ’ง Light watering
Sep 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Oct 3.5" 2.9" 0.6" ๐Ÿ’ง Light watering
Nov โ€” 2.1" 0" โ„๏ธ Dormant
Dec โ€” 1.6" 0" โ„๏ธ Dormant

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

Kale 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.

Kale needs ~600 GDD — county provides 1,590 GDD Excellent fit

Kale Planting Timeline โ€” Floyd County, IA

Kale Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 โ€“ Apr 3
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 24 Apr 24 โ€“ May 15
Harvest June 26 Jun 26 โ€“ Aug 21
Fall Sowing July 15 Jul 15 โ€“ Jul 29

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

159 days in Floyd County

Growing Tips for Kale in Floyd County

Direct sow Kale outdoors after May 01 in Floyd County when soil has warmed and frost danger has passed.

Common pests for Kale 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 or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Kale Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow 2nd year flower stalks to dry. Harvest pods when tan.
Storage Store airtight; viable 5 years at 35ยฐF, under 50% humidity.

Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) โ€” they all cross.

Frequently Asked Questions

When should I plant Kale in Floyd County, IA?

Floyd County is in Zone 4b with an average last frost of May 1. Plan your Kale planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Floyd County, IA?

Floyd County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Floyd County gardeners in Zone 4b 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 Floyd County, IA. Local conditions may vary. Last updated: April 2026.