When to Plant Pole Beans in Multnomah County, OR
Top priorities for Multnomah County, Oregon gardeners in May
We've pulled the most time-sensitive tasks for Multnomah County, Oregon this May and put them front and centre. Tackle them in order.
-
Indoor seed-starting week for pole beans
Your window is short. These crops want several weeks of indoor growth before they go outside.
Looking ahead to June
- First harvests: pole beans
Pole beans are climbing varieties of green beans that produce over a much longer season than bush types. They require trellising but yield more per square foot.
Multnomah County, Oregon is in USDA Zone 9a. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.
At an elevation of 357 feet, Multnomah County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Pole Beans to ensure they mature before fall.
Multnomah County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.3
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 Multnomah County
How your county's soil matches Pole Beans's growing requirements.
Soil pH
Your soil pH (5.8–6.3) overlaps with Pole Beans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Multnomah County is excellent for Pole Beans — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Pole Beans.
Organic Matter
Organic matter is excellent (4.5%) — Pole Beans will thrive.
How to Plant Pole Beans
Succession Planting Pole Beans
Sow every 6.3 weeks. Last sowing by Aug 18 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Pole Beans
Pole Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Pole Beans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.8" | 0" | ❄️ Dormant |
| Feb | — | 4.1" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.3" | 2" | 💧 Light watering |
| May | 4.3" | 2.3" | 2" | 💧 Light watering |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Aug | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 6" | 0" | ❄️ Dormant |
| Dec | — | 4.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Multnomah County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Pole Beans 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.
Pole Beans Planting Timeline — Multnomah County, OR
Pole Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 3 | Mar 3 – Mar 17 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 14 | Apr 14 – May 5 |
| Harvest | June 16 | Jun 16 – Aug 11 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
55–70 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
196 days in Multnomah County
Growing Tips for Pole Beans in Multnomah County
Direct sow Pole Beans outdoors after April 14 in Multnomah County when soil has warmed and frost danger has passed.
Common pests for Pole Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Provide sturdy 6-8 foot poles, tepees, or trellises. Direct sow after last frost. Pick regularly to encourage continued production. Beans fix nitrogen benefiting following crops.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Pole Beans in Other Locations
Frequently Asked Questions
When should I plant Pole Beans in Multnomah County, OR?
Multnomah County is in Zone 9a with an average last frost of April 14. Plan your Pole Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Multnomah County, OR?
Multnomah County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 14 and first fall frost is October 27.
Your Multnomah County Garden Planner — Free
A 24-page printable planner built for Multnomah County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.