When to Plant Pawpaw in Marion County, OR
Your May gardening checklist
Your Marion County, Oregon garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Get pawpaw in the ground
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
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.
Marion County, Oregon is in USDA Zone 8b. The average last spring frost is April 20 and the first fall frost is October 30, giving you a growing season of approximately 193 days.
At an elevation of 422 feet, Marion County receives approximately 50.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Pawpaw during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Pawpaw root diseases.
Marion County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.8
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 Marion County
How your county's soil matches Pawpaw's growing requirements.
Soil pH
Your soil pH (5.4–6.8) overlaps with Pawpaw's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Marion County is excellent for Pawpaw — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Pawpaw will thrive.
How to Plant Pawpaw
Plant Water Budget
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 | — | 6.9" | 0" | ❄️ Dormant |
| Feb | — | 5.1" | 0" | ❄️ Dormant |
| Mar | — | 4.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Jun | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jul | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Aug | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Sep | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Oct | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Nov | — | 8.2" | 0" | ❄️ Dormant |
| Dec | — | 9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Marion 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 — Marion County, OR
Pawpaw Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 11 | May 11 – May 25 |
· 120" apart · Rows 144" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
1095–2555 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
193 days in Marion County
Growing Tips for Pawpaw in Marion County
Direct sow Pawpaw outdoors after April 20 in Marion County when soil has warmed and frost danger has passed.
Your 193.0-day growing season in Marion County is tight for Pawpaw (1095.0-2555.0 days to maturity). Start indoors and choose early-maturing varieties.
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 Marion County, OR?
Marion County is in Zone 8b with an average last frost of April 20. Plan your Pawpaw planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marion County, OR?
Marion County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 20 and first fall frost is October 30.
Your Marion County Garden Planner — Free
A 24-page printable planner built for Marion 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.