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When to Plant Cabbage in Cassia County, ID

Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

Cassia County, Idaho is in USDA Zone 5b. The average last spring frost is May 15 and the first fall frost is October 1, giving you a growing season of approximately 139 days.

At an elevation of 8,089 feet, Cassia County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Cabbage during the growing season. With low rainfall, drip irrigation is essential for growing Cabbage successfully. Mulch heavily to conserve soil moisture.

Cassia County, ID (Zone 5b) Short season
139 days
Last Spring Frost May 15
139 growing days
First Fall Frost October 1

Cassia County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jul 11 – Sep 5
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jul 17 – Sep 11
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Aug 11 – Oct 6

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 Cassia County

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

Soil pH

Your soil pH (6.3โ€“8.2) overlaps with Cabbage's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Cabbage.

How to Plant Cabbage

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 Cabbage

2
successive plantings in your 139-day season

Sow every 6.9 weeks. Last sowing by Jun 23 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 551 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cabbage

Cabbage needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Cabbage Needs Rainfall You Supplement Action
Jan โ€” 1.1" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 1.8" 0" โ„๏ธ Dormant
May 3.9" 2.3" 1.6" ๐Ÿ’ง Light watering
Jun 3.9" 1.1" 2.8" ๐Ÿšฟ Regular watering
Jul 3.9" 1.5" 2.4" ๐Ÿšฟ Regular watering
Aug 3.9" 1.7" 2.2" ๐Ÿšฟ Regular watering
Sep 3.9" 1.3" 2.6" ๐Ÿšฟ Regular watering
Oct 3.9" 1.6" 2.3" ๐Ÿšฟ Regular watering
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

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

Cabbage 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.

Cabbage needs ~1,220 GDD — county provides 2,119 GDD Excellent fit

Cabbage Planting Timeline โ€” Cassia County, ID

Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 โ€“ Apr 24
Transplant Outdoors May 15 May 15 โ€“ May 29
Direct Sow May 1 May 1 โ€“ May 22
Harvest July 17 Jul 17 โ€“ Sep 11
Fall Sowing July 23 Jul 23 โ€“ Aug 6

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 โ€”
July Fall Sowing Harvest
August Fall Sowing Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

139 days in Cassia County

Growing Tips for Cabbage in Cassia County

Direct sow Cabbage outdoors after May 15 in Cassia County when soil has warmed and frost danger has passed.

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

Cassia County receives only 18" of rain annually. Cabbage needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cabbage in Cassia County, ID?

Cassia County is in Zone 5b with an average last frost of May 15. Plan your Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cassia County, ID?

Cassia County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 15 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Cassia County, ID. Local conditions may vary. Last updated: April 2026.