When to Plant Watercress in Yamhill County, OR
Yamhill County, Oregon gardeners: here's your May plan
We've pulled the most time-sensitive tasks for Yamhill County, Oregon this May and put them front and centre. Tackle them in order.
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Time to start watercress inside
These need a head start before your last frost (April 15). Sow into cells now so you're ready to transplant in a few weeks.
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Collect watercress at their peak
If you can't use it all right away, check the food-preservation section of your planner.
June prep starts now
- First harvests: watercress
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.
Yamhill County, Oregon is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 27, giving you a growing season of approximately 195 days.
At an elevation of 476 feet, Yamhill County receives approximately 54.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Watercress during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.
Yamhill County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Yamhill County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (5.4–6.2) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Yamhill 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
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Watercress
Sow every 4.6 weeks. Last sowing by Aug 28 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
Plant Water Budget
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 | — | 7.4" | 0" | ❄️ Dormant |
| Feb | — | 6.4" | 0" | ❄️ Dormant |
| Mar | — | 5.1" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.5" | 3" | 💧 Light watering |
| May | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
| Jun | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Jul | 6.5" | 0.9" | 5.6" | 🚿 Regular watering |
| Aug | 6.5" | 1" | 5.5" | 🚿 Regular watering |
| Sep | 6.5" | 2.4" | 4.1" | 🚿 Regular watering |
| Oct | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Nov | — | 9.3" | 0" | ❄️ Dormant |
| Dec | — | 8.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Yamhill 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 Planting Timeline — Yamhill County, OR
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Direct Sow | April 1 | Apr 1 – Apr 22 |
| Harvest | May 27 | May 27 – Jul 1 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| 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
1.5"/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 8b
📆 Growing Season
195 days in Yamhill County
Growing Tips for Watercress in Yamhill County
Direct sow Watercress outdoors after April 15 in Yamhill County when soil has warmed and frost danger has passed.
Your generous 195.0-day season in Yamhill 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 →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in Yamhill County, OR?
Yamhill County is in Zone 8b with an average last frost of April 15. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Yamhill County, OR?
Yamhill County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 27.
Your Yamhill County Garden Planner — Free
A 24-page printable planner built for Yamhill 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.