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When to plant Cabbage in Rio Blanco County, CO

Rio Blanco County gardeners should plant Cabbage between May 19 and June 9 in spring. With Rio Blanco County's Zone 5b climate (last frost June 2), Cabbage needs 60–100 days to mature — plant by June 9 for a full harvest. A second sowing from July 9 to July 23 extends the harvest into fall.

When to Plant Cabbage in Rio Blanco County, CO

Cabbage
Rio Blanco County, Colorado Zone 5b July

Your July gardening checklist

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Rio Blanco County, Colorado.

Avg. last frost June 2
Avg. first frost September 17
Soil temp (4") 54°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Get cabbage seeds going inside

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Direct-sow cabbage for cool weather

    Your first frost is about 7 weeks away — plenty of time for these to mature.

To set up a strong August, finish these tasks
  • First harvests: cabbage

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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.

Rio Blanco County, Colorado is in USDA Zone 5b. The average last spring frost is June 2 and the first fall frost is September 17, giving you a growing season of approximately 107 days.

At an elevation of 6,974 feet, Rio Blanco County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, 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.

Rio Blanco County, CO (Zone 5b) Short season
107 days
Last Spring Frost June 2
107 growing days
First Fall Frost September 17

Rio Blanco County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Cabbage Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 21 – Sep 15
Recommended (50%) ✗ May not fit
Start indoors: Apr 28 Transplant: Jun 2 🍅 Harvest: Aug 4 – Sep 29
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jun 20 🍅 Harvest: Aug 22 – Oct 17

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 Rio Blanco County

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

Soil pH

Your soil pH (6.4–7.7) overlaps with Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Rio Blanco County is excellent for Cabbage — 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.

How Much Cabbage to Grow

2-4 lbs
Average yield per plant
3
Plants per person
7.5 sq ft
Space per person

For a family of 4, plant approximately 12 cabbage plants in about 30 sq ft. In Rio Blanco County's 107-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Cabbage Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 176 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.1" 0" ❄️ Dormant
Jun 3.9" 1.3" 2.6" 🚿 Regular watering
Jul 3.9" 1.4" 2.5" 🚿 Regular watering
Aug 3.9" 1.9" 2" 🚿 Regular watering
Sep 3.9" 1.6" 2.3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Rio Blanco County). Supplement amounts are based on average rainfall — 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" — 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.

Cabbage needs ~1,160 GDD — county provides 1,551 GDD Excellent fit

Cabbage Planting Timeline — Rio Blanco County, CO

Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 28 Apr 28 – May 12
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 19 May 19 – Jun 9
Harvest August 4 Aug 4 – Sep 29
Fall Sowing July 9 Jul 9 – Jul 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

107 days in Rio Blanco County

Growing Tips for Cabbage in Rio Blanco County

Direct sow Cabbage outdoors after June 02 in Rio Blanco County when soil has warmed and frost danger has passed.

Your 107.0-day growing season in Rio Blanco County is tight for Cabbage (60.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Rio Blanco County receives only 19" of rain annually. Cabbage needs consistent moisture — 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 Rio Blanco County, CO?

Rio Blanco County is in Zone 5b with an average last frost of June 2. Plan your Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rio Blanco County, CO?

Rio Blanco County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 2 and first fall frost is September 17.

When should I plant Cabbage in Rio Blanco County, CO?

In Rio Blanco County, CO, plant Cabbage after the last frost (around June 2) and before the first frost (around September 17). Best results when soil holds above 50°F.

What growing zone is Rio Blanco County, CO for Cabbage?

Rio Blanco County sits in USDA Zone 5b. Cabbage grows reliably in zones 1a through 10b, so it's a good fit here.

Can Cabbage grow in Rio Blanco County's climate?

Yes — Cabbage grows well in Rio Blanco County's temperate climate. Rio Blanco County averages a 107-day frost-free season, with last frost around June 2 and first frost around September 17.

🌱

Your Rio Blanco County Garden Planner — Free

A 22-page printable planner built for Rio Blanco 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 Rio Blanco County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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