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When to Plant Sweet Pea in Clallam County, WA

Clallam County, Washington Zone 8b June

What to do in June

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

Avg. last frost April 23
Avg. first frost October 26
Soil temp (4") 80°F
Watering High
Pest pressure High
Daylight 15.8 hrs

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Sweet peas (Lathyrus odoratus) are beloved cool-season climbing annuals grown primarily for their intensely fragrant, ruffled blooms in shades of pink, purple, red, and white. They thrive in cool spring conditions, climbing trellises to 4–6 feet, and make outstanding cut flowers. Bloom ceases once summer heat arrives, making early sowing critical for a long cutting season.

Clallam County, Washington is in USDA Zone 8b. The average last spring frost is April 23 and the first fall frost is October 26, giving you a growing season of approximately 186 days.

At an elevation of 194 feet, Clallam County receives approximately 54.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sweet Pea to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Pea root diseases.

Annual Blooms in Spring Pollinator-friendly Good for cutting Fragrant
Clallam County, WA (Zone 8b) Moderate season
186 days
Last Spring Frost April 23
186 growing days
First Fall Frost October 26

Clallam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Sweet Pea Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Transplant: Apr 14 🌸 Bloom: Jun 23 – Sep 1
Recommended (50%) ✓ Fits season (46 days to spare)
Transplant: Apr 23 🌸 Bloom: Jul 2 – Sep 10
Safe Start (90%) ✓ Fits season (44 days to spare)
Transplant: May 9 🌸 Bloom: Jul 18 – Sep 26

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 Clallam County

How your county's soil matches Sweet Pea's growing requirements.

Soil pH

Your soil pH (5.7–6.8) is more acidic than Sweet Pea prefers (7.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Sweet Pea will thrive.

How to Plant Sweet Pea

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 9 weeks before your first frost date for a fall harvest.

Succession Planting Sweet Pea

3
successive plantings in your 186-day season

Sow every 7.4 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Sweet Pea Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sweet Pea

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

Month Sweet Pea Needs Rainfall You Supplement Action
Jan 8.9" 0" ❄️ Dormant
Feb 5.5" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 4.3" 4.6" 0" ✅ Rainfall sufficient
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 1.1" 3.2" 🚿 Regular watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 9.1" 0" ❄️ Dormant
Dec 7.9" 0" ❄️ Dormant

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

Sweet Pea 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.

Sweet Pea needs ~919 GDD — county provides 2,278 GDD Excellent fit

Sweet Pea Planting Timeline — Clallam County, WA

Sweet Pea Planting Calendar

Activity When Date Range
Bloom November 2 Nov 2 – Jan 11
Fall Sowing August 24 Aug 24 – Sep 7

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Bloom
February
March
April
May
June
July
August Fall Sowing
September Fall Sowing
October
November Bloom
December Bloom

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 7–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

186 days in Clallam County

Growing Tips for Sweet Pea in Clallam County

Direct sow Sweet Pea outdoors after April 23 in Clallam County when soil has warmed and frost danger has passed.

Common pests for Sweet Pea in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Soak seeds 24 hours before sowing to soften the hard seed coat; nick the seed coat with a file for the fastest germination. In cold zones (2–6), direct-sow as soon as soil can be worked, 4–6 weeks before last frost; seedlings tolerate light frost but not a hard freeze. In zones 7–9, fall-sow 8–10 weeks before first frost for earlier, stronger spring bloom. Provide a trellis or netting from the start. Feed with low-nitrogen, high-potassium fertilizer once buds form. Pick blooms regularly — even one mature seed pod stops flower production. All plant parts are mildly toxic if eaten.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Pea in Clallam County, WA?

Clallam County is in Zone 8b with an average last frost of April 23. Plan your Sweet Pea planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clallam County, WA?

Clallam County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 23 and first fall frost is October 26.

🌱

Your Clallam County Garden Planner — Free

A 22-page printable planner built for Clallam 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 Clallam County, WA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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