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When to Plant Broccoli in Delta, UT

Broccoli
Millard County, Utah Zone 6a June

Your June planting checklist for Millard County, Utah

Your garden in Millard County, Utah is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 16
Avg. first frost September 30
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Sow broccoli in trays indoors

    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.

July will be here before you know it — start on
  • First harvests: broccoli
  • Fall sowing: 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.

Delta, Utah is in USDA Zone 6a. 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 84°F, so choose short-season varieties of Broccoli to ensure they mature before fall.

Delta, UT (Zone 6a) Short season
137 days
Last Spring Frost May 16
137 growing days
First Fall Frost September 30

Delta Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Broccoli 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.

Soil Compatibility in Delta

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

Soil pH

Your soil pH (6.5–8.0) is more alkaline than Broccoli prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). 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 137-day season

Sow every 6.9 weeks. Last sowing by Jul 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 22.

Broccoli 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 — 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 4.3" 2.7" 1.6" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Millard 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 ~975 GDD — county provides 1,781 GDD Excellent fit

Broccoli Planting Timeline — Delta, UT

Broccoli Planting Calendar

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

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Fall Sowing Harvest
September
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 6a

📆 Growing Season

137 days in Millard County

Growing Tips for Broccoli in Delta

Direct sow Broccoli outdoors after May 16 in Millard 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.

Millard County receives only 24" 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.

🌱

Your Millard County Garden Planner — Free

A 22-page printable planner built for Millard County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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: June 2026.