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When to Plant Broccoli in Chittenden County, VT

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.

Chittenden County, Vermont is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is October 5, giving you a growing season of approximately 146 days.

At an elevation of 235 feet, Chittenden County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Broccoli to ensure they mature before fall.

Chittenden County, VT (Zone 4b) Short season
146 days
Last Spring Frost May 12
146 growing days
First Fall Frost October 5

Chittenden County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Start indoors: Mar 25 Transplant: May 6 🍅 Harvest: Jul 8 – Aug 19
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 14 – Aug 25
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Apr 20 Transplant: Jun 1 🍅 Harvest: Aug 3 – Sep 14

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Broccoli needs ~862 GDD — county provides 1,679 GDD Excellent fit

Broccoli Planting Timeline โ€” Chittenden County, VT

Broccoli Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow May 5 May 5 โ€“ May 26
Fall Sowing July 13 Jul 13 โ€“ Jul 27
Harvest July 14 Jul 14 โ€“ Aug 25

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing Harvest
August 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 4b

Growing Season

146 days

Growing Tips for Chittenden 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 Chittenden County, VT?

Chittenden County is in Zone 4b with an average last frost of May 12. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chittenden County, VT?

Chittenden County, Vermont is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Chittenden County gardeners in Zone 4b 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 Chittenden County, VT. Local conditions may vary. Last updated: April 2026.