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When to Plant Watercress in Lincoln County, OR

Lincoln County, Oregon Zone 9a May

May in Lincoln County, Oregon — your action list

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

Avg. last frost April 19
Avg. first frost October 31
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Begin indoor sowing: watercress

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Bring in the watercress

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

June will be here before you know it — start on
  • 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, Oregon is in USDA Zone 9a. The average last spring frost is April 19 and the first fall frost is October 31, giving you a growing season of approximately 195 days.

At an elevation of 267 feet, Lincoln County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Watercress to ensure they mature before fall.

Lincoln County, OR (Zone 9a) Moderate season
195 days
Last Spring Frost April 19
195 growing days
First Fall Frost October 31
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Lincoln County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (128 days to spare)
Start indoors: Mar 7 Transplant: Apr 4 🍅 Harvest: May 16 – Jun 20
Recommended (50%) ✓ Fits season (118 days to spare)
Start indoors: Mar 22 Transplant: Apr 19 🍅 Harvest: May 31 – Jul 5
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Apr 13 Transplant: May 11 🍅 Harvest: Jun 22 – Jul 27

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 (5.5–6.4) 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.

Organic Matter

Organic matter is excellent (4.9%) — 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 195-day season

Sow every 4.6 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Sep 05.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,059 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 6.1" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 6.5" 3.2" 3.3" 🚿 Regular watering
May 6.5" 2" 4.5" 🚿 Regular watering
Jun 6.5" 1.5" 5" 🚿 Regular watering
Jul 6.5" 0.6" 5.9" 🚿 Regular watering
Aug 6.5" 0.7" 5.8" 🚿 Regular watering
Sep 6.5" 1.8" 4.7" 🚿 Regular watering
Oct 6.5" 3.8" 2.7" 💧 Light watering
Nov 6.3" 0" ❄️ Dormant
Dec 5.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct 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 ~612 GDD — county provides 2,388 GDD Excellent fit

Watercress Planting Timeline — Lincoln County, OR

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow March 29 Mar 29 – Apr 19
Harvest May 31 May 31 – Jul 5
Fall Sowing September 5 Sep 5 – Sep 19

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
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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

195 days in Lincoln County

Growing Tips for Watercress in Lincoln County

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

Your generous 195.0-day season in Lincoln 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 Lincoln County, OR?

Lincoln County is in Zone 9a with an average last frost of April 19. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lincoln County, OR?

Lincoln County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 19 and first fall frost is October 31.

🌱

Your Lincoln County Garden Planner — Free

A 24-page printable planner built for Lincoln 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 Lincoln County, OR. 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.