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When to Plant Broccoli in Millard County, UT

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.

Millard County, Utah is in USDA Zone 5b. The average last spring frost is May 16 and the first fall frost is September 30, giving you a growing season of approximately 137 days.

At an elevation of 6,525 feet, Millard County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Broccoli to ensure they mature before fall.

Millard County, UT (Zone 5b) Short season
137 days
Last Spring Frost May 16
137 growing days
First Fall Frost September 30

Millard County Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 9 – Aug 20
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Jul 18 – Aug 29
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: May 5 Transplant: Jun 9 🍅 Harvest: Aug 11 – 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 387 gal / 100 sq ft
Drought risk

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

Broccoli needs ~975 GDD — county provides 1,781 GDD Excellent fit

Broccoli Planting Timeline โ€” Millard County, UT

Broccoli Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 โ€“ Apr 25
Transplant Outdoors May 16 May 16 โ€“ May 30
Direct Sow May 2 May 2 โ€“ May 23
Fall Sowing July 22 Jul 22 โ€“ Aug 5
Harvest July 18 Jul 18 โ€“ Aug 29

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 โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

137 days

Growing Tips for Millard County

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

Level Up Your Garden

๐ŸŒพ 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 35ยฐF, under 50% humidity.

Isolate 1/2 mile from other brassicas. Biennial โ€” must overwinter roots.

Frequently Asked Questions

When should I plant Broccoli in Millard County, UT?

Millard County is in Zone 5b with an average last frost of May 16. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Millard County, UT?

Millard County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 16 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Millard County gardeners in Zone 5b 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 Millard County, UT. Local conditions may vary. Last updated: April 2026.