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When to Plant Kale in Natrona County, WY

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.

Natrona County, Wyoming is in USDA Zone 4b. The average last spring frost is May 19 and the first fall frost is September 23, giving you a growing season of approximately 127 days.

At an elevation of 6,332 feet, Natrona County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Kale to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Kale successfully. Mulch heavily to conserve soil moisture.

Natrona County, WY (Zone 4b) Short season
127 days
Last Spring Frost May 19
127 growing days
First Fall Frost September 23

Natrona County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 8
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 22

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 Natrona County

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

Soil pH

Your soil pH (6.5โ€“7.6) overlaps with Kale's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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

2
successive plantings in your 127-day season

Sow every 5.7 weeks. Last sowing by Jul 15 to harvest before frost.

For a dedicated fall crop, sow by Jul 01.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.5″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 471 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 1.3" 0" โ„๏ธ Dormant
May 3.5" 1.8" 1.7" ๐Ÿ’ง Light watering
Jun 3.5" 1.1" 2.4" ๐Ÿšฟ Regular watering
Jul 3.5" 1.1" 2.4" ๐Ÿšฟ Regular watering
Aug 3.5" 1.5" 2" ๐Ÿšฟ Regular watering
Sep 3.5" 1.1" 2.4" ๐Ÿšฟ Regular watering
Oct โ€” 1.1" 0" โ„๏ธ Dormant
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Natrona 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 ~735 GDD — county provides 1,555 GDD Excellent fit

Kale Planting Timeline โ€” Natrona County, WY

Kale Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 โ€“ Apr 21
Transplant Outdoors May 19 May 19 โ€“ Jun 2
Direct Sow May 12 May 12 โ€“ Jun 2
Harvest July 14 Jul 14 โ€“ Sep 8
Fall Sowing July 1 Jul 1 โ€“ Jul 15

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

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

127 days in Natrona County

Growing Tips for Kale in Natrona County

Direct sow Kale outdoors after May 19 in Natrona 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.

Recommended Kale Varieties for Natrona County

Cold-hardy kale that improves in flavor after frost

Winterbor Red Russian Dwarf Blue Curled

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 Natrona County, WY?

Natrona County is in Zone 4b with an average last frost of May 19. Plan your Kale planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Natrona County, WY?

Natrona County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 19 and first fall frost is September 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Natrona 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 Natrona County, WY. Local conditions may vary. Last updated: April 2026.