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When to Plant Cauliflower in Linn 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.

Linn County, Oregon is in USDA Zone 8a. The average last spring frost is April 22 and the first fall frost is October 25, giving you a growing season of approximately 186 days.

At an elevation of 259 feet, Linn County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Cauliflower to ensure they mature before fall.

Linn County, OR (Zone 8a) Moderate season
186 days
Last Spring Frost April 22
186 growing days
First Fall Frost October 25

Linn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Aug 12
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 19
Safe Start (90%) ✓ Fits season (70 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11

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
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,093 gal / 100 sq ft
Cauliflower needs ~833 GDD — county provides 1,999 GDD Excellent fit

Cauliflower Planting Timeline โ€” Linn County, OR

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 8 Apr 8 โ€“ Apr 29
Fall Sowing August 16 Aug 16 โ€“ Aug 30
Harvest June 17 Jun 17 โ€“ Aug 19

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 Transplant Outdoors Direct Sow
May Transplant Outdoors
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
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 8a

Growing Season

186 days

Growing Tips for Linn 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 Linn County, OR?

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

What planting zone is Linn County, OR?

Linn County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 22 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

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