When to Plant in Portland, OR

Portland's maritime climate is excellent for gardening — Zone 8b with a last frost around March 23rd and long, mild growing seasons. The city's wet winters and springs give way to a dry summer perfect for irrigation-managed warm-season crops.

Portland gardeners enjoy a long cool-season growing window and a productive summer once the soil warms. The main challenge is getting warm-season crops started early enough indoors to produce before summer's end. Slug pressure in spring is significant.

This month in Portland: October 2026

Portland's first frost usually holds off until around November 15, so October is still a growing month. The bigger change is the rain. Once it settles in, the slugs come out, and young lettuce and spinach are their favorite.

Get the last sowings in early: radishes, arugula, and spinach sown in the first week or two still make it before the short days slow everything down. Garlic goes in this month too, before the soil turns to mud.

Pick the green tomatoes by mid-month; with the rain and cool nights they'll split or rot before they ripen outside. Let them finish on the counter. Cut the spent plants at the soil line and put a layer of leaves or compost over the empty beds so the rain doesn't pack them down.

Updated October 8, 2026

FAQ

When is the last frost date in Portland, OR?

Portland's average last frost date is around March 23rd. The mild maritime climate means tomatoes and peppers can be started indoors in February for an early March transplant.

What grows best in Portland?

Cool-season crops thrive almost year-round: kale, lettuce, chard, broccoli, peas, and root vegetables. Tomatoes, peppers, and squash do well in summer with the right variety selection.

How do I deal with slugs in Portland?

Slugs are a major spring pest in Portland. Use iron phosphate bait (safe for pets), copper tape around raised beds, and plant slug-resistant varieties. Go out at night with a flashlight to hand-pick.

Can I grow tomatoes in Portland?

Yes! Choose early-maturing varieties (under 70 days). Plant in your warmest, most protected spot facing south. September is often the best harvest month as summer fog patterns shift.

How does Plan My Garden help Portland gardeners?

Enter your Portland zip code for personalized planting dates tuned to the Willamette Valley's maritime climate.