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When to Plant Chard in San Benito County, CA

San Benito County, California Zone 9b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in San Benito County, California.

Avg. last frost February 21
Avg. first frost November 29
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for chard

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Coming up in June — start thinking about
  • First harvests: chard

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Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

San Benito County, California is in USDA Zone 9b. 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 94°F, providing good warmth for Chard during the growing season. With low rainfall, drip irrigation is essential for growing Chard successfully. Mulch heavily to conserve soil moisture.

San Benito County, CA (Zone 9b) 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 (185 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🍅 Harvest: Apr 2 – May 21
Recommended (50%) ✓ Fits season (176 days to spare)
Start indoors: Jan 24 Transplant: Feb 21 🍅 Harvest: Apr 18 – Jun 6
Safe Start (90%) ✓ Fits season (152 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 22

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 Chard's growing requirements.

Soil pH

Your soil pH (6.5–7.4) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in San Benito County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Chard

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 Chard

6
successive plantings in your 281-day season

Sow every 5.7 weeks. Last sowing by Sep 30 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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chard

Chard 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 Chard Needs Rainfall You Supplement Action
Jan 2.5" 0" ❄️ Dormant
Feb 3.5" 2.6" 0.9" 💧 Light watering
Mar 3.5" 2.2" 1.3" 💧 Light watering
Apr 3.5" 1.1" 2.4" 🚿 Regular watering
May 3.5" 0.3" 3.2" 🚿 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" 0.1" 3.4" 🚿 Regular watering
Oct 3.5" 0.5" 3" 🚿 Regular watering
Nov 3.5" 1.3" 2.2" 🚿 Regular watering
Dec 2.3" 0" ❄️ Dormant

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

Chard 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.

Chard needs ~1,128 GDD — county provides 5,781 GDD Excellent fit

Chard Planting Timeline — San Benito County, CA

Chard Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 – Feb 7
Transplant Outdoors February 21 Feb 21 – Mar 7
Direct Sow January 31 Jan 31 – Feb 21
Harvest April 18 Apr 18 – Jun 6
Fall Sowing October 4 Oct 4 – Oct 18

Plant 1" deep · 15" apart · 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
August
September
October Fall Sowing
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · 2-3 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

281 days in San Benito County

Growing Tips for Chard in San Benito County

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

Summer highs in San Benito County reach 94°F — grow Chard as a spring or fall crop. Use shade cloth if planting in summer.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

San Benito County is in Zone 9b with an average last frost of February 21. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Benito County, CA?

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

🌱

Your San Benito County Garden Planner — Free

A 24-page printable planner built for San Benito 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 San Benito 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.