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When to Plant Kale in Linn County, KS

Linn County, Kansas Zone 6b May

May to-do list for Linn County, Kansas

Your garden in Linn County, Kansas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Time to start kale inside

    Label every cell. You will absolutely forget which is which otherwise.

Coming up in June — start thinking about
  • First harvests: kale

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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.

Linn County, Kansas is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 434 feet, Linn County receives approximately 33 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Kale during the growing season.

Linn County, KS (Zone 6b) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Linn County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 30 – Jul 25
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 30
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 12

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 Linn County

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

Soil pH

Your soil pH (6.6–7.2) is within Kale's preferred range (6.0–7.5).

Soil Texture

The loam soil in Linn County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Kale.

How to Plant Kale

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

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

Succession Planting Kale

4
successive plantings in your 199-day season

Sow every 5.7 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 220 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 3.5" 3.5" 0" ✅ Rainfall sufficient
May 3.5" 5.4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.6" 0" ✅ Rainfall sufficient
Jul 3.5" 4.2" 0" ✅ Rainfall sufficient
Aug 3.5" 4.5" 0" ✅ Rainfall sufficient
Sep 3.5" 2.6" 0.9" 💧 Light watering
Oct 3.5" 2.3" 1.2" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Linn County). Supplement amounts are based on average rainfall — 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" — 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.

Kale needs ~870 GDD — county provides 2,885 GDD Excellent fit

Kale Planting Timeline — Linn County, KS

Kale Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Harvest June 4 Jun 4 – Jul 30
Fall Sowing August 16 Aug 16 – Aug 30

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

199 days in Linn County

Growing Tips for Kale in Linn County

Direct sow Kale outdoors after April 09 in Linn 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 →

🌾 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 35°F, under 50% humidity.

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

Frequently Asked Questions

When should I plant Kale in Linn County, KS?

Linn County is in Zone 6b with an average last frost of April 9. Plan your Kale planting based on this frost date — see the calendar above for exact timing.

What planting zone is Linn County, KS?

Linn County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 25.

🌱

Your Linn County Garden Planner — Free

A 24-page printable planner built for Linn County (Zone 6b). 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 Linn County, KS. Local conditions may vary. Last updated: May 2026.

Sources & credits

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