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When to Plant Broccoli in Sanpete 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.

Sanpete County, Utah is in USDA Zone 5b. The average last spring frost is May 21 and the first fall frost is September 28, giving you a growing season of approximately 130 days.

At an elevation of 6,969 feet, Sanpete County receives approximately 14.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, 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.

Sanpete County, UT (Zone 5b) Short season
130 days
Last Spring Frost May 21
130 growing days
First Fall Frost September 28

Sanpete County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jul 15 – Aug 26
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: Apr 16 Transplant: May 21 🍅 Harvest: Jul 23 – Sep 3
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Aug 12 – Sep 23

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 Sanpete County

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

Soil pH

Your soil pH (6.5โ€“7.8) is more alkaline than Broccoli prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Sanpete County is excellent for Broccoli โ€” 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.

Succession Planting Broccoli

2
successive plantings in your 130-day season

Sow every 6.9 weeks. Last sowing by Jun 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 20.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 751 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.5" 0" โ„๏ธ Dormant
May 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Jun 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jul 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Aug 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Sep 4.3" 1.3" 3" 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 Sanpete County). Supplement amounts are based on average rainfall โ€” 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" 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.

Broccoli needs ~1,088 GDD — county provides 1,885 GDD Excellent fit

Broccoli Planting Timeline โ€” Sanpete County, UT

Broccoli Planting Calendar

Activity When Date Range
Start Indoors April 16 Apr 16 โ€“ Apr 30
Transplant Outdoors May 21 May 21 โ€“ Jun 4
Direct Sow May 7 May 7 โ€“ May 28
Harvest July 23 Jul 23 โ€“ Sep 3
Fall Sowing July 20 Jul 20 โ€“ Aug 3

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
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

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

130 days in Sanpete County

Growing Tips for Broccoli in Sanpete County

Direct sow Broccoli outdoors after May 21 in Sanpete County when soil has warmed and frost danger has passed.

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

Sanpete County receives only 14" of rain annually. Broccoli needs consistent moisture โ€” 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 →

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 Sanpete County, UT?

Sanpete County is in Zone 5b with an average last frost of May 21. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sanpete County, UT?

Sanpete County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 21 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

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