When to Plant Watercress in Okanogan County, WA
May in the garden — Okanogan County, Washington
Your garden in Okanogan County, Washington is working on a schedule, even when you're not. Here's where you should be this May.
-
Move watercress into the garden
Your last frost (May 13) has passed. These warm-season crops can handle outdoor soil now.
Before June arrives, get these ready
- Starting indoors: watercress
- 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.
Okanogan County, Washington is in USDA Zone 6b. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.
At an elevation of 3,788 feet, Okanogan County receives approximately 21.3 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.
Okanogan County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.5
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 Okanogan County
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (5.4–6.5) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Okanogan 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 (5.6%) — 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 Jul 28 to harvest before frost.
For a dedicated fall crop, sow by Jul 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 | — | 2.9" | 0" | ❄️ Dormant |
| Feb | — | 2.4" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | 6.5" | 1.3" | 5.2" | 🚿 Regular watering |
| Jun | 6.5" | 0.7" | 5.8" | 🚿 Regular watering |
| Jul | 6.5" | 0.3" | 6.2" | 🚿 Regular watering |
| Aug | 6.5" | 0.4" | 6.1" | 🚿 Regular watering |
| Sep | 6.5" | 0.7" | 5.8" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 3.6" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Okanogan 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 — Okanogan County, WA
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | June 24 | Jun 24 – Jul 29 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing |
| 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
136 days in Okanogan County
Growing Tips for Watercress in Okanogan County
Direct sow Watercress outdoors after May 13 in Okanogan 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.
Okanogan County receives only 21" 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 →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in Okanogan County, WA?
Okanogan County is in Zone 6b with an average last frost of May 13. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Okanogan County, WA?
Okanogan County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 13 and first fall frost is September 26.
Your Okanogan County Garden Planner — Free
A 24-page printable planner built for Okanogan 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.