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When to Plant Chard in Merced County, CA

Merced County, California Zone 9a May

Merced County, California gardeners: here's your May plan

Your Merced County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Harvest chard as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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.

Merced County, California is in USDA Zone 9a. The average last spring frost is February 24 and the first fall frost is November 28, giving you a growing season of approximately 277 days.

At an elevation of 269 feet, Merced County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°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.

Merced County, CA (Zone 9a) Year-round
277 days
Last Spring Frost February 24
277 growing days
First Fall Frost November 28

Merced County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (184 days to spare)
Start indoors: Jan 9 Transplant: Feb 6 🍅 Harvest: Apr 3 – May 22
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Apr 21 – Jun 9
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 1

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 Merced County

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

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Chard prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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 277-day season

Sow every 5.7 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 03.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.3″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,532 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 4.4" 0" ❄️ Dormant
Feb 3.5" 4" 0" ✅ Rainfall sufficient
Mar 3.5" 2.6" 0.9" 💧 Light watering
Apr 3.5" 1.7" 1.8" 🚿 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" 0.7" 2.8" 🚿 Regular watering
Nov 3.5" 1.6" 1.9" 🚿 Regular watering
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Merced 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 ~839 GDD — county provides 4,239 GDD Excellent fit

Chard Planting Timeline — Merced County, CA

Chard Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors February 24 Feb 24 – Mar 10
Direct Sow February 3 Feb 3 – Feb 24
Harvest April 21 Apr 21 – Jun 9
Fall Sowing October 3 Oct 3 – Oct 17

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
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 · 1-2 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Merced County

Growing Tips for Chard in Merced County

Direct sow Chard outdoors after February 24 in Merced County when soil has warmed and frost danger has passed.

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 Merced County, CA?

Merced County is in Zone 9a with an average last frost of February 24. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Merced County, CA?

Merced County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 24 and first fall frost is November 28.

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Your Merced County Garden Planner — Free

A 24-page printable planner built for Merced County (Zone 9a). 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 Merced 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.