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When to Plant Watercress in Lincoln County, WA

Lincoln County, Washington Zone 6b May

What to do in May

We've pulled the most time-sensitive tasks for Lincoln County, Washington this May and put them front and centre. Tackle them in order.

Avg. last frost May 19
Avg. first frost September 26
Soil temp (4") 54°F
Watering Critical
Pest pressure Low
Daylight 14.9 hrs
  1. Get watercress in the ground

    Your last frost (May 19) has passed. These warm-season crops can handle outdoor soil now.

  2. Put watercress seeds straight in the ground

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Coming up in June — start thinking about
  • Starting indoors: watercress
  • 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.

Lincoln County, Washington is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is September 26, giving you a growing season of approximately 130 days.

At an elevation of 2,955 feet, Lincoln County receives approximately 21.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watercress during the growing season.

Lincoln County, WA (Zone 6b) Short season
130 days
Last Spring Frost May 19
130 growing days
First Fall Frost September 26

Lincoln County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 19 – Jul 24
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jun 30 – Aug 4
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: May 12 Transplant: Jun 16 🍅 Harvest: Jul 28 – Sep 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 Lincoln County

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

Soil pH

Your soil pH (5.5–6.6) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Watercress is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is excellent (4.3%) — Watercress will thrive.

How to Plant Watercress

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

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

Succession Planting Watercress

3
successive plantings in your 130-day season

Sow every 4.6 weeks. Last sowing by Jul 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 1,452 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 3.2" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 6.5" 1.1" 5.4" 🚿 Regular watering
Jun 6.5" 1" 5.5" 🚿 Regular watering
Jul 6.5" 0.3" 6.2" 🚿 Regular watering
Aug 6.5" 0.5" 6" 🚿 Regular watering
Sep 6.5" 0.8" 5.7" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Lincoln 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 ~762 GDD — county provides 1,982 GDD Excellent fit

Watercress Planting Timeline — Lincoln County, WA

Watercress Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 5 May 5 – May 26
Harvest June 30 Jun 30 – Aug 4
Fall Sowing July 18 Jul 18 – Aug 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

130 days in Lincoln County

Growing Tips for Watercress in Lincoln County

Direct sow Watercress outdoors after May 19 in Lincoln County when soil has warmed and frost danger has passed.

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

Lincoln County receives only 22" of rain annually. Watercress needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Lincoln County, WA?

Lincoln County is in Zone 6b with an average last frost of May 19. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lincoln County, WA?

Lincoln County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is September 26.

🌱

Your Lincoln County Garden Planner — Free

A 24-page printable planner built for Lincoln County (Zone 6b). 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 Lincoln 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.