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When to Plant Cauliflower in Columbia County, OR

Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Columbia County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 29, giving you a growing season of approximately 198 days.

At an elevation of 396 feet, Columbia County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Cauliflower during the growing season.

Columbia County, OR (Zone 8a) Moderate season
198 days
Last Spring Frost April 14
198 growing days
First Fall Frost October 29

Columbia County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

How Much Cauliflower to Grow

1-2 lbs
Average yield per plant
3
Plants per person
6 sq ft
Space per person

For a family of 4, plant approximately 12 cauliflower plants in about 24 sq ft. In Columbia County's 198-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Cauliflower

Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cauliflower Needs Rainfall You Supplement Action
Jan โ€” 6.5" 0" โ„๏ธ Dormant
Feb โ€” 4.8" 0" โ„๏ธ Dormant
Mar โ€” 4.9" 0" โ„๏ธ Dormant
Apr 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
May 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Jun 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Jul 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Aug 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Sep 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Oct 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Nov โ€” 7.6" 0" โ„๏ธ Dormant
Dec โ€” 7.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Columbia County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cauliflower Planting Timeline โ€” Columbia County, OR

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow March 31 Mar 31 โ€“ Apr 21
Harvest June 9 Jun 9 โ€“ Aug 11
Fall Sowing August 20 Aug 20 โ€“ Sep 3

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

High โ€” keep soil consistently moist

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

198 days in Columbia County

Growing Tips for Columbia County

Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in Columbia County, OR?

Columbia County is in Zone 8a with an average last frost of April 14. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Columbia County, OR?

Columbia County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

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