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When to Plant Potatoes in Trinity County, CA

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Trinity County, California is in USDA Zone 7b. The average last spring frost is April 19 and the first fall frost is October 25, giving you a growing season of approximately 189 days.

At an elevation of 61 feet, Trinity County receives approximately 30.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 79ยฐF, so choose short-season varieties of Potatoes to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Potatoes will need more frequent watering and organic matter to retain nutrients.

Trinity County, CA (Zone 7b) Moderate season
189 days
Last Spring Frost April 19
189 growing days
First Fall Frost October 25

Trinity County Soil Profile

Soil Type

Sandy Loam

Soil pH

6-7.1

Drainage

Well Drained

How Much Potatoes to Grow

3-5 lbs
Average yield per plant
5
Plants per person
10 sq ft
Space per person

For a family of 4, plant approximately 20 potatoes plants in about 40 sq ft. In Trinity County's 189-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Potatoes

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

Month Potatoes Needs Rainfall You Supplement Action
Jan โ€” 6.2" 0" โ„๏ธ Dormant
Feb โ€” 6.6" 0" โ„๏ธ Dormant
Mar โ€” 5" 0" โ„๏ธ Dormant
Apr 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
May 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Oct 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 4.9" 0" โ„๏ธ Dormant

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

Potatoes Planting Timeline โ€” Trinity County, CA

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 โ€“ Mar 15
Transplant Outdoors May 3 May 3 โ€“ May 17
Direct Sow April 26 Apr 26 โ€“ May 17
Harvest July 12 Jul 12 โ€“ Sep 20

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

70โ€“120 days

๐Ÿงช Soil pH

Needs 5โ€“6.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

189 days in Trinity County

Growing Tips for Trinity County

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Potatoes in Trinity County, CA?

Trinity County is in Zone 7b with an average last frost of April 19. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Trinity County, CA?

Trinity County, California is in USDA Hardiness Zone 7b. The average last spring frost is April 19 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Trinity County gardeners in Zone 7b 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 Trinity County, CA. Local conditions may vary. Last updated: April 2026.