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When to Plant Sorrel in Stanislaus County, CA

Stanislaus County, California Zone 9a April

Stanislaus County, California gardeners: here's your April plan

April is a pivotal month for Stanislaus County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 24
Avg. first frost November 28
Soil temp (4") 61°F
Watering High
Pest pressure High
Daylight 13 hrs
  1. Harvest sorrel as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before May arrives, get these ready
  • First harvests: sorrel

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Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and salads.

Stanislaus 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 2,887 feet, Stanislaus County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Sorrel during the growing season. With low rainfall, drip irrigation is essential for growing Sorrel successfully. Mulch heavily to conserve soil moisture.

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

Stanislaus County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (191 days to spare)
Start indoors: Jan 9 Transplant: Jan 30 🍅 Harvest: Mar 13 – May 15
Recommended (50%) ✓ Fits season (179 days to spare)
Start indoors: Jan 27 Transplant: Feb 17 🍅 Harvest: Mar 31 – Jun 2
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Mar 21 Transplant: Apr 11 🍅 Harvest: May 23 – Jul 25

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 Stanislaus County

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Sorrel prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Sorrel.

How to Plant Sorrel

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Sorrel

8
successive plantings in your 277-day season

Sow every 4.6 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 03.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,287 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Sorrel

Sorrel needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sorrel Needs Rainfall You Supplement Action
Jan 3.1" 0" ❄️ Dormant
Feb 4.3" 3.5" 0.8" 💧 Light watering
Mar 4.3" 2.1" 2.2" 🚿 Regular watering
Apr 4.3" 1.3" 3" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.5" 2.8" 🚿 Regular watering
Dec 2.2" 0" ❄️ Dormant

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

Sorrel 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.

Sorrel needs ~1,025 GDD — county provides 5,699 GDD Excellent fit

Sorrel Planting Timeline — Stanislaus County, CA

Sorrel Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 – Feb 10
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow February 3 Feb 3 – Feb 24
Harvest March 31 Mar 31 – Jun 2
Fall Sowing October 3 Oct 3 – Oct 17

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Stanislaus County

Growing Tips for Sorrel in Stanislaus County

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

Your generous 278.0-day season in Stanislaus County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.

Stanislaus County receives only 15" of rain annually. Sorrel needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sorrel in Stanislaus County, CA?

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

What planting zone is Stanislaus County, CA?

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

🌱

Your Stanislaus County Garden Planner — Free

A 24-page printable planner built for Stanislaus 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 Stanislaus County, CA. Local conditions may vary. Last updated: April 2026.

Sources & credits

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