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When to Plant Cauliflower in Coos 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.

Coos County, Oregon is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Cauliflower during the growing season.

Coos County, OR (Zone 8b) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (120 days to spare)
Start indoors: Jan 31 Transplant: Mar 7 🍅 Harvest: May 2 – Jul 4
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: May 17 – Jul 19
Safe Start (90%) ✓ Fits season (118 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 19

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
1.5″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,780 gal / 100 sq ft
Cauliflower needs ~1,298 GDD — county provides 4,053 GDD Excellent fit

Cauliflower Planting Timeline โ€” Coos County, OR

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors March 22 Mar 22 โ€“ Apr 5
Direct Sow March 8 Mar 8 โ€“ Mar 29
Fall Sowing September 10 Sep 10 โ€“ Sep 24
Harvest May 17 May 17 โ€“ Jul 19

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

55โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8b

Growing Season

242 days

Growing Tips for Coos 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

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Frequently Asked Questions

When should I plant Cauliflower in Coos County, OR?

Coos County is in Zone 8b with an average last frost of March 22. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coos County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Coos County, OR. Local conditions may vary. Last updated: April 2026.