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When to Plant Cucumber in Marin County, CA

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Marin County, California is in USDA Zone 10a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 302 feet, Marin County receives approximately 36 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Cucumber to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Cucumber will need more frequent watering and organic matter to retain nutrients.

Marin County, CA (Zone 10a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Marin County Soil Profile

Soil Type

Sandy Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Start indoors: Jan 13 Transplant: Feb 17 🍅 Harvest: Apr 14 – Jun 9
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Jan 29 Transplant: Mar 5 🍅 Harvest: Apr 30 – Jun 25
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 30

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 Marin County

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

Soil pH

Your soil pH (6.0โ€“6.9) is within Cucumber's preferred range (6.0โ€“7.0).

Soil Texture

Sandy soil in Marin County warms quickly in spring but drains fast. Cucumber will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Cucumber.

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Succession Planting Cucumber

6
successive plantings in your 273-day season

Sow every 5.7 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,775 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cucumber

Cucumber needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cucumber Needs Rainfall You Supplement Action
Jan โ€” 7.2" 0" โ„๏ธ Dormant
Feb 6.5" 6.5" 0" โœ… Rainfall sufficient
Mar 6.5" 6.2" 0.3" ๐Ÿ’ง Light watering
Apr 6.5" 2.7" 3.8" ๐Ÿšฟ Regular watering
May 6.5" 1" 5.5" ๐Ÿšฟ Regular watering
Jun 6.5" 0.2" 6.3" ๐Ÿšฟ Regular watering
Jul 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Aug 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Sep 6.5" 0.4" 6.1" ๐Ÿšฟ Regular watering
Oct 6.5" 1.4" 5.1" ๐Ÿšฟ Regular watering
Nov 6.5" 3.5" 3" ๐Ÿ’ง Light watering
Dec โ€” 6.9" 0" โ„๏ธ Dormant

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

Cucumber 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.

Cucumber needs ~645 GDD — county provides 2,945 GDD Excellent fit

Cucumber Planting Timeline โ€” Marin County, CA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 โ€“ Feb 12
Transplant Outdoors March 5 Mar 5 โ€“ Mar 19
Direct Sow February 26 Feb 26 โ€“ Mar 19
Harvest April 30 Apr 30 โ€“ Jun 25

Plant 0.5" deep ยท 24" apart ยท Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 10a

๐Ÿ“† Growing Season

273 days in Marin County

Growing Tips for Cucumber in Marin County

Direct sow Cucumber outdoors after February 26 in Marin County when soil has warmed and frost danger has passed.

Sandy soil in Marin County dries quickly โ€” mulch Cucumber with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Cucumber in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Marin County, CA?

Marin County is in Zone 10a with an average last frost of February 26. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Marin County, CA?

Marin County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 26 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Marin County gardeners in Zone 10a 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 Marin County, CA. Local conditions may vary. Last updated: April 2026.