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When to Plant Sorrel in Island County, WA

Island County, Washington Zone 8b May

May in the garden — Island County, Washington

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

Avg. last frost March 30
Avg. first frost November 3
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Time to start sorrel inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Harvest sorrel as they ripen

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

A few tasks this May that'll pay off in June
  • 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.

Island County, Washington is in USDA Zone 8b. The average last spring frost is March 30 and the first fall frost is November 3, giving you a growing season of approximately 218 days.

At an elevation of 9 feet, Island County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Sorrel during the growing season.

Island County, WA (Zone 8b) Long season
218 days
Last Spring Frost March 30
218 growing days
First Fall Frost November 3

Island County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (123 days to spare)
Start indoors: Feb 15 Transplant: Mar 15 🍅 Harvest: Apr 26 – Jun 28
Recommended (50%) ✓ Fits season (120 days to spare)
Start indoors: Feb 23 Transplant: Mar 23 🍅 Harvest: May 4 – Jul 6
Safe Start (90%) ✓ Fits season (110 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 4 – Aug 6

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 Island County

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

Soil pH

Your soil pH (5.6–6.7) is within Sorrel's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.3%) — Sorrel will thrive.

How to Plant Sorrel

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Sorrel

6
successive plantings in your 218-day season

Sow every 4.6 weeks. Last sowing by Sep 04 to harvest before frost.

For a dedicated fall crop, sow by Aug 25.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 239 gal / 100 sq ft

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 6.8" 0" ❄️ Dormant
Feb 4.7" 0" ❄️ Dormant
Mar 4.3" 4.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 0.7" 3.6" 🚿 Regular watering
Aug 4.3" 0.8" 3.5" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 4.3" 7" 0" ✅ Rainfall sufficient
Dec 7.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Island 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 ~688 GDD — county provides 2,997 GDD Excellent fit

Sorrel Planting Timeline — Island County, WA

Sorrel Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 16 Mar 16 – Apr 6
Harvest May 4 May 4 – Jul 6
Fall Sowing August 25 Aug 25 – Sep 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

218 days in Island County

Growing Tips for Sorrel in Island County

Direct sow Sorrel outdoors after March 30 in Island County when soil has warmed and frost danger has passed.

Your generous 218.0-day season in Island County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.

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 Island County, WA?

Island County is in Zone 8b with an average last frost of March 30. Plan your Sorrel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Island County, WA?

Island County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is March 30 and first fall frost is November 3.

🌱

Your Island County Garden Planner — Free

A 24-page printable planner built for Island County (Zone 8b). 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 Island County, WA. 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.