When to Plant Potatoes in Stevens County, WA
May in Stevens County, Washington — your action list
A quick May briefing for Stevens County, Washington gardeners — what's urgent, what's next, and what can wait.
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Plant out potatoes
Frost risk is low now in Stevens County, Washington. If you've been covering beds overnight, you can stop.
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Direct-sow potatoes
These tolerate cool soil, so you're not gambling by sowing now.
Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.
Stevens County, Washington is in USDA Zone 6b. The average last spring frost is May 10 and the first fall frost is September 24, giving you a growing season of approximately 137 days.
At an elevation of 1,751 feet, Stevens County receives approximately 24.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Potatoes to ensure they mature before fall.
Stevens County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.3
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 Stevens County
How your county's soil matches Potatoes's growing requirements.
Soil pH
Your soil pH (5.3–6.3) is within Potatoes's preferred range (5.0–6.5).
Soil Texture
The silt loam soil in Stevens County is excellent for Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Potatoes will thrive.
How to Plant Potatoes
Succession Planting Potatoes
Sow every 8 weeks. Last sowing by May 27 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Potatoes
Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Aug | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Sep | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Oct | — | 2.3" | 0" | ❄️ Dormant |
| Nov | — | 4.2" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Stevens County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Potatoes 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.
Potatoes Planting Timeline — Stevens County, WA
Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 15 | Mar 15 – Mar 29 |
| Transplant Outdoors | May 24 | May 24 – Jun 7 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | August 2 | Aug 2 – Oct 11 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
70–120 days
🧪 Soil pH
Needs 5–6.5 · Your soil: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
137 days in Stevens County
Growing Tips for Potatoes in Stevens County
Direct sow Potatoes outdoors after May 10 in Stevens County when soil has warmed and frost danger has passed.
Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
Stevens County receives only 24" of rain annually. Potatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.
Recommended Potatoes Varieties for Stevens County
Early-maturing potatoes for your season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Potatoes in Other Locations
Frequently Asked Questions
When should I plant Potatoes in Stevens County, WA?
Stevens County is in Zone 6b with an average last frost of May 10. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Stevens County, WA?
Stevens County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 10 and first fall frost is September 24.
Your Stevens County Garden Planner — Free
A 24-page printable planner built for Stevens 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.