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When to Plant Collard Greens in Fresno County, CA

Fresno County, California Zone 9b May

Your May planting checklist for Fresno County, California

Here's what deserves your attention in Fresno County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost March 2
Avg. first frost November 23
Soil temp (4") 72°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Start harvesting collard greens

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to June
  • First harvests: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Fresno County, California is in USDA Zone 9b. The average last spring frost is March 2 and the first fall frost is November 23, giving you a growing season of approximately 266 days.

At an elevation of 2,276 feet, Fresno County receives approximately 14.9 inches of rainfall annually with predominantly loam soil. Summer highs average 100°F, so Collard Greens may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.

Fresno County, CA (Zone 9b) Long season
266 days
Last Spring Frost March 2
266 growing days
First Fall Frost November 23

Fresno County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Start indoors: Jan 19 Transplant: Feb 16 🍅 Harvest: Apr 13 – Jun 15
Recommended (50%) ✓ Fits season (147 days to spare)
Start indoors: Feb 2 Transplant: Mar 2 🍅 Harvest: Apr 27 – Jun 29
Safe Start (90%) ✓ Fits season (99 days to spare)
Start indoors: Apr 13 Transplant: May 11 🍅 Harvest: Jul 6 – Sep 7

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 Fresno County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (6.5–7.5) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Fresno County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Collard Greens.

How to Plant Collard Greens

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 Collard Greens

5
successive plantings in your 266-day season

Sow every 6.3 weeks. Last sowing by Sep 09 to harvest before frost.

For a dedicated fall crop, sow by Sep 28.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.2″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,604 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Collard Greens

Collard Greens 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 Collard Greens Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 3.5" 2.3" 1.2" 💧 Light watering
Apr 3.5" 1" 2.5" 🚿 Regular watering
May 3.5" 0.4" 3.1" 🚿 Regular watering
Jun 3.5" 0.1" 3.4" 🚿 Regular watering
Jul 3.5" 0" 3.5" 🚿 Regular watering
Aug 3.5" 0" 3.5" 🚿 Regular watering
Sep 3.5" 0.2" 3.3" 🚿 Regular watering
Oct 3.5" 0.6" 2.9" 🚿 Regular watering
Nov 3.5" 1.3" 2.2" 🚿 Regular watering
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Fresno County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Collard Greens 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" — every day above 50°F 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.

Collard Greens needs ~1,625 GDD — county provides 6,650 GDD Excellent fit

Collard Greens Planting Timeline — Fresno County, CA

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow February 9 Feb 9 – Mar 2
Harvest April 27 Apr 27 – Jun 29
Fall Sowing September 28 Sep 28 – Oct 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

266 days in Fresno County

Growing Tips for Collard Greens in Fresno County

Direct sow Collard Greens outdoors after March 02 in Fresno County when soil has warmed and frost danger has passed.

With summer highs reaching 100°F in Fresno County, provide afternoon shade for Collard Greens and water deeply in the morning.

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

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Fresno County, CA?

Fresno County is in Zone 9b with an average last frost of March 2. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fresno County, CA?

Fresno County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 2 and first fall frost is November 23.

🌱

Your Fresno County Garden Planner — Free

A 24-page printable planner built for Fresno County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Fresno County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.