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When to plant Broccoli in Archuleta County, CO

Archuleta County sits in USDA Zone 5b. Plant Broccoli between May 30 (after last frost on June 13) and June 20. A second sowing from July 9 to July 23 extends the harvest into fall.

When to Plant Broccoli in Archuleta County, CO

Broccoli
Archuleta County, Colorado Zone 5b July

July in the garden — Archuleta County, Colorado

We've pulled the most time-sensitive tasks for Archuleta County, Colorado this July and put them front and centre. Tackle them in order.

Avg. last frost June 13
Avg. first frost September 17
Soil temp (4") 63°F
Watering High
Pest pressure High
Daylight 14.3 hrs
  1. Get broccoli 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. Kick off the fall garden with broccoli

    Keep young seedlings shaded and moist in summer heat. A row of taller crops works as natural shade.

Before August arrives, get these ready
  • First harvests: broccoli

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Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.

Archuleta County, Colorado is in USDA Zone 5b. The average last spring frost is June 13 and the first fall frost is September 17, giving you a growing season of approximately 96 days.

At an elevation of 5,346 feet, Archuleta County receives approximately 14 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Broccoli during the growing season. With low rainfall, drip irrigation is essential for growing Broccoli successfully. Mulch heavily to conserve soil moisture.

Archuleta County, CO (Zone 5b) Very short season
96 days
Last Spring Frost June 13
96 growing days
First Fall Frost September 17

Archuleta County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Broccoli Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Aug 8 – Sep 19
Recommended (50%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Aug 15 – Sep 26
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Aug 26 – Oct 7

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 Archuleta County

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

Soil pH

Your soil pH (6.3–7.9) is more alkaline than Broccoli prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Broccoli.

How to Plant Broccoli

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 Broccoli to Grow

1-2 lbs
Average yield per plant
3
Plants per person
7.5 sq ft
Space per person

For a family of 4, plant approximately 12 broccoli plants in about 30 sq ft. In Archuleta County's 96-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Broccoli Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 397 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Broccoli

Broccoli needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Broccoli Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.9" 0" ❄️ Dormant
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.3" 3" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Archuleta County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Broccoli 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.

Broccoli needs ~1,031 GDD — county provides 1,320 GDD Good fit

Broccoli Planting Timeline — Archuleta County, CO

Broccoli Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 – May 23
Transplant Outdoors June 13 Jun 13 – Jun 27
Direct Sow May 30 May 30 – Jun 20
Harvest August 15 Aug 15 – Sep 26
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
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

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

96 days in Archuleta County

Growing Tips for Broccoli in Archuleta County

Direct sow Broccoli outdoors after June 13 in Archuleta County when soil has warmed and frost danger has passed.

Your 96.0-day growing season in Archuleta County is tight for Broccoli (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Archuleta County receives only 14" of rain annually. Broccoli needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Broccoli Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow plants to flower 2nd year; collect dry pods.
Storage Store airtight; viable 5 years at 35°F, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.

Frequently Asked Questions

When should I plant Broccoli in Archuleta County, CO?

Archuleta County is in Zone 5b with an average last frost of June 13. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.

What planting zone is Archuleta County, CO?

Archuleta County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 13 and first fall frost is September 17.

When should I plant Broccoli in Archuleta County, CO?

In Archuleta County, CO, plant Broccoli after the last frost (around June 13) and before the first frost (around September 17). Best results when soil holds above 50°F.

What growing zone is Archuleta County, CO for Broccoli?

Archuleta County sits in USDA Zone 5b. Broccoli grows reliably in zones 2a through 11b, so it's a good fit here.

Can Broccoli grow in Archuleta County's climate?

Yes — Broccoli grows well in Archuleta County's temperate climate. Archuleta County averages a 96-day frost-free season, with last frost around June 13 and first frost around September 17.

🌱

Your Archuleta County Garden Planner — Free

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

Sources & credits

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