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When to Plant Cucumber in Colusa 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.

Colusa County, California is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 112 feet, Colusa County receives approximately 29.8 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Cucumber during the growing season.

Colusa County, CA (Zone 9a) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Colusa County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (151 days to spare)
Start indoors: Jan 26 Transplant: Mar 2 🍅 Harvest: Apr 27 – Jun 22
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Feb 6 Transplant: Mar 13 🍅 Harvest: May 8 – Jul 3
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15

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 Colusa County

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

Soil pH

Your soil pH (6.6โ€“7.5) is more alkaline than Cucumber prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Colusa County is excellent for Cucumber โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Cucumber is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is moderate (2.5%). 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 267-day season

Sow every 5.7 weeks. Last sowing by Sep 19 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.8″/week
Watering frequency 2-3 times/week
Season total 4,224 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€” 6.2" 0" โ„๏ธ Dormant
Feb โ€” 6.7" 0" โ„๏ธ Dormant
Mar 6.5" 4.7" 1.8" ๐Ÿ’ง Light watering
Apr 6.5" 2" 4.5" ๐Ÿšฟ Regular watering
May 6.5" 0.7" 5.8" ๐Ÿšฟ Regular watering
Jun 6.5" 0.1" 6.4" ๐Ÿšฟ Regular watering
Jul 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Aug 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Sep 6.5" 0.3" 6.2" ๐Ÿšฟ Regular watering
Oct 6.5" 1.1" 5.4" ๐Ÿšฟ Regular watering
Nov 6.5" 3" 3.5" ๐Ÿšฟ Regular watering
Dec โ€” 4.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Colusa 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 ~1,230 GDD — county provides 5,473 GDD Excellent fit

Cucumber Planting Timeline โ€” Colusa County, CA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 โ€“ Feb 20
Transplant Outdoors March 13 Mar 13 โ€“ Mar 27
Direct Sow March 6 Mar 6 โ€“ Mar 27
Harvest May 8 May 8 โ€“ Jul 3

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Transplant Outdoors Direct Sow
April โ€”
May Harvest
June Harvest
July Harvest
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: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

267 days in Colusa County

Growing Tips for Cucumber in Colusa County

Direct sow Cucumber outdoors after March 06 in Colusa County when soil has warmed and frost danger has passed.

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 Colusa County, CA?

Colusa County is in Zone 9a with an average last frost of March 6. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Colusa County, CA?

Colusa County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Colusa County gardeners in Zone 9a 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 Colusa County, CA. Local conditions may vary. Last updated: April 2026.