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When to Plant Broccoli in Collin County, TX

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.

Collin County, Texas is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94ยฐF, providing good warmth for Broccoli during the growing season. Clay soil retains moisture well for Broccoli, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Broccoli root diseases.

Collin County, TX (Zone 8a) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Collin County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (149 days to spare)
Start indoors: Jan 26 Transplant: Mar 2 🍅 Harvest: May 4 – Jun 15
Recommended (50%) ✓ Fits season (150 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: May 12 – Jun 23
Safe Start (90%) ✓ Fits season (135 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jun 13 – Jul 25

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 Collin County

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

Soil pH

Your soil pH (7.3โ€“7.8) is more alkaline than Broccoli prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (43% clay) in Collin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.7%). 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

5
successive plantings in your 255-day season

Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Sep 11.

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
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€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 2.2" 0" โ„๏ธ Dormant
Mar 4.3" 4.3" 0" โœ… Rainfall sufficient
Apr 4.3" 6.9" 0" โœ… Rainfall sufficient
May 4.3" 10.2" 0" โœ… Rainfall sufficient
Jun 4.3" 9.9" 0" โœ… Rainfall sufficient
Jul 4.3" 7.3" 0" โœ… Rainfall sufficient
Aug 4.3" 8.4" 0" โœ… Rainfall sufficient
Sep 4.3" 6.5" 0" โœ… Rainfall sufficient
Oct 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Nov 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Collin 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 ~1,538 GDD — county provides 5,227 GDD Excellent fit

Broccoli Planting Timeline โ€” Collin County, TX

Broccoli Planting Calendar

Activity When Date Range
Start Indoors February 3 Feb 3 โ€“ Feb 17
Transplant Outdoors March 10 Mar 10 โ€“ Mar 24
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest May 12 May 12 โ€“ Jun 23
Fall Sowing September 11 Sep 11 โ€“ Sep 25

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May Harvest
June Harvest
July โ€”
August โ€”
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

255 days in Collin County

Growing Tips for Broccoli in Collin County

Direct sow Broccoli outdoors after March 10 in Collin County when soil has warmed and frost danger has passed.

With Collin County's clay soil (43% clay), work in 3-4 inches of compost before planting Broccoli. Avoid tilling when soil is wet to prevent compaction.

Summer highs in Collin County reach 94ยฐF โ€” grow Broccoli as a spring or fall crop. Use shade cloth if planting in summer.

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

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.

Recommended Broccoli Varieties for Collin County

Heat-tolerant broccoli โ€” plant as early spring or fall crop

Arcadia Marathon Green Magic

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 Collin County, TX?

Collin County is in Zone 8a with an average last frost of March 10. Plan your Broccoli planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Collin County, TX?

Collin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Collin County gardeners in Zone 8a 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 Collin County, TX. Local conditions may vary. Last updated: April 2026.