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When to Plant Watercress in Pacific County, WA

Pacific County, Washington Zone 9a May

Your May game plan for Pacific County, Washington

Your garden in Pacific County, Washington is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 18
Avg. first frost October 29
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Fire up the seed-starting tray: watercress

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Collect watercress at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of June
  • First harvests: watercress

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Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.

Pacific County, Washington is in USDA Zone 9a. The average last spring frost is April 18 and the first fall frost is October 29, giving you a growing season of approximately 194 days.

At an elevation of 14 feet, Pacific County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Watercress during the growing season.

Pacific County, WA (Zone 9a) Moderate season
194 days
Last Spring Frost April 18
194 growing days
First Fall Frost October 29

Pacific County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🍅 Harvest: May 17 – Jun 21
Recommended (50%) ✓ Fits season (117 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (130 days to spare)
Start indoors: Apr 11 Transplant: May 9 🍅 Harvest: Jun 20 – 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 Pacific County

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

Soil pH

Your soil pH (5.6–6.2) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — Watercress will thrive.

How to Plant Watercress

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

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

Succession Planting Watercress

5
successive plantings in your 194-day season

Sow every 4.6 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 818 gal / 100 sq ft

Monthly Watering Guide for Watercress

Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watercress Needs Rainfall You Supplement Action
Jan 7.2" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 2.8" 3.7" 🚿 Regular watering
Jun 6.5" 1.8" 4.7" 🚿 Regular watering
Jul 6.5" 0.9" 5.6" 🚿 Regular watering
Aug 6.5" 0.9" 5.6" 🚿 Regular watering
Sep 6.5" 1.7" 4.8" 🚿 Regular watering
Oct 6.5" 4.2" 2.3" 💧 Light watering
Nov 8" 0" ❄️ Dormant
Dec 6.7" 0" ❄️ Dormant

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

Watercress 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.

Watercress needs ~725 GDD — county provides 2,813 GDD Excellent fit

Watercress Planting Timeline — Pacific County, WA

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow March 28 Mar 28 – Apr 18
Harvest May 30 May 30 – Jul 4
Fall Sowing September 3 Sep 3 – Sep 17

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

194 days in Pacific County

Growing Tips for Watercress in Pacific County

Direct sow Watercress outdoors after April 18 in Pacific County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in Pacific County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.

Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watercress in Pacific County, WA?

Pacific County is in Zone 9a with an average last frost of April 18. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pacific County, WA?

Pacific County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 18 and first fall frost is October 29.

🌱

Your Pacific County Garden Planner — Free

A 24-page printable planner built for Pacific 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pacific 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.