When to Plant Radish in Multnomah County, OR
Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.
Multnomah County, Oregon is in USDA Zone 8b. 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 Radish 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 Radish's growing requirements.
Soil pH
Your soil pH (5.8–6.3) overlaps with Radish's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Multnomah County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Radish.
Organic Matter
Organic matter is excellent (4.5%) — Radish will thrive.
How to Plant Radish
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Sep 22 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
Plant Water Budget
Radish Planting Timeline — Multnomah County, OR
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
| Harvest | April 28 | Apr 28 – May 19 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
22–35 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
196 days in Multnomah County
Growing Tips for Radish in Multnomah County
Direct sow Radish outdoors after April 14 in Multnomah County when soil has warmed and frost danger has passed.
Your generous 196.0-day season in Multnomah County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.
Common pests for Radish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Multnomah County, OR?
Multnomah County is in Zone 8b with an average last frost of April 14. Plan your Radish 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 8b. The average last spring frost is April 14 and first fall frost is October 27.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Multnomah County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.
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