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When to Plant Kale in San Benito County, CA

Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.

San Benito County, California is in USDA Zone 9a. The average last spring frost is February 21 and the first fall frost is November 29, giving you a growing season of approximately 281 days.

At an elevation of 149 feet, San Benito County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Kale during the growing season. With low rainfall, drip irrigation is essential for growing Kale successfully. Mulch heavily to conserve soil moisture.

San Benito County, CA (Zone 9a) Year-round
281 days
Last Spring Frost February 21
281 growing days
First Fall Frost November 29

San Benito County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (178 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🍅 Harvest: Apr 2 – May 28
Recommended (50%) ✓ Fits season (169 days to spare)
Start indoors: Jan 24 Transplant: Feb 21 🍅 Harvest: Apr 18 – Jun 13
Safe Start (90%) ✓ Fits season (145 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 29

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 San Benito County

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

Soil pH

Your soil pH (6.5โ€“7.4) is within Kale's preferred range (6.0โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Kale.

How to Plant Kale

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Kale

6
successive plantings in your 281-day season

Sow every 5.7 weeks. Last sowing by Sep 20 to harvest before frost.

For a dedicated fall crop, sow by Oct 04.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.2″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,826 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Kale

Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Kale Needs Rainfall You Supplement Action
Jan โ€” 2.5" 0" โ„๏ธ Dormant
Feb 3.5" 2.6" 0.9" ๐Ÿ’ง Light watering
Mar 3.5" 2.2" 1.3" ๐Ÿ’ง Light watering
Apr 3.5" 1.1" 2.4" ๐Ÿšฟ Regular watering
May 3.5" 0.3" 3.2" ๐Ÿšฟ Regular watering
Jun 3.5" 0.1" 3.4" ๐Ÿšฟ Regular watering
Jul 3.5" 0" 3.5" ๐Ÿšฟ Regular watering
Aug 3.5" 0" 3.5" ๐Ÿšฟ Regular watering
Sep 3.5" 0.1" 3.4" ๐Ÿšฟ Regular watering
Oct 3.5" 0.5" 3" ๐Ÿšฟ Regular watering
Nov 3.5" 1.3" 2.2" ๐Ÿšฟ Regular watering
Dec โ€” 2.3" 0" โ„๏ธ Dormant

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

Kale 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.

Kale needs ~1,230 GDD — county provides 5,781 GDD Excellent fit

Kale Planting Timeline โ€” San Benito County, CA

Kale Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 โ€“ Feb 7
Transplant Outdoors February 21 Feb 21 โ€“ Mar 7
Direct Sow January 31 Jan 31 โ€“ Feb 21
Harvest April 18 Apr 18 โ€“ Jun 13
Fall Sowing October 4 Oct 4 โ€“ Oct 18

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

281 days in San Benito County

Growing Tips for Kale in San Benito County

Direct sow Kale outdoors after February 21 in San Benito County when soil has warmed and frost danger has passed.

Summer highs in San Benito County reach 94ยฐF โ€” grow Kale as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Kale in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Kale Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow 2nd year flower stalks to dry. Harvest pods when tan.
Storage Store airtight; viable 5 years at 35ยฐF, under 50% humidity.

Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) โ€” they all cross.

Frequently Asked Questions

When should I plant Kale in San Benito County, CA?

San Benito County is in Zone 9a with an average last frost of February 21. Plan your Kale planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Benito County, CA?

San Benito County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 21 and first fall frost is November 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Benito 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 San Benito County, CA. Local conditions may vary. Last updated: April 2026.