When to Plant Pawpaw in Washington County, ID
Pawpaw is the largest native fruit tree in North America, producing tropical-tasting custard-like fruits. Young trees prefer shade but fruiting trees need good light.
Washington County, Idaho is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.
At an elevation of 4,048 feet, Washington County receives approximately 17.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Pawpaw during the growing season. With low rainfall, drip irrigation is essential for growing Pawpaw successfully. Mulch heavily to conserve soil moisture.
Washington County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 Washington County
How your county's soil matches Pawpaw's growing requirements.
Soil pH
Your soil pH (6.2–7.8) overlaps with Pawpaw's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Washington County is excellent for Pawpaw — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Pawpaw.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Pawpaw.
How to Plant Pawpaw
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Pawpaw
Pawpaw needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Pawpaw Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jul | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Aug | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Oct | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Washington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Pawpaw 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.
Pawpaw Planting Timeline — Washington County, ID
Pawpaw Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 30 | May 30 – Jun 13 |
· 120" apart · Rows 144" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
1095–2555 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
145 days in Washington County
Growing Tips for Pawpaw in Washington County
Direct sow Pawpaw outdoors after May 09 in Washington County when soil has warmed and frost danger has passed.
Your 145.0-day growing season in Washington County is tight for Pawpaw (1095.0-2555.0 days to maturity). Start indoors and choose early-maturing varieties.
Washington County receives only 18" of rain annually. Pawpaw needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Plant at least two genetically distinct trees for cross-pollination. Provide shade for young trees. Fruits ripen in fall and have a very short shelf life. Harvest when slightly soft.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Pawpaw in Other Locations
Frequently Asked Questions
When should I plant Pawpaw in Washington County, ID?
Washington County is in Zone 6a with an average last frost of May 9. Plan your Pawpaw planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, ID?
Washington County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 1.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Washington County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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