What to plant this week in Portland, OR
Portland gardeners are in full summer swing as temperatures hover near 15°F minimums, making this the perfect week to harvest your early melons and squash before the late-December frost. With the last frost safely behind us since March 1, you can finally focus on pulling those cool-season crops like garlic and edamame while enjoying a bountiful crop of bush beans and zucchini.
The next 7 days
Portland, ORGrowing in Portland right now
- Portland's notorious summer fog often brings cooler nights that slow growth; be sure to harvest cucumbers and squash promptly before they get too heavy in the damp air.
- Our local clay-heavy soils retain moisture well, so reduce watering frequency for newly sown basil and borage this week to prevent root rot in our humid pockets.
- Take advantage of the mild 8b climate to start your autumn succession planting; sow bush beans and pole beans now as a second crop before the winter squash vines finish their run.
Sow this week
17 crops- Basil
- Borage
- Bush Bean
- Cleome (Spider Flower)
- Cucumber
- French Marigold
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Summer Savory
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Yellow Summer Squash
- Zinnia
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
36 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Lima Bean
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and pole beans every two weeks for a continuous harvest through summer.
- Thin out dense seedlings of zucchini and yellow summer squash to prevent overcrowding.
- Apply a light layer of mulch around established crops to retain soil moisture as summer heat builds.
Pest & disease watch
- Watch for spider mites on your French marigolds and zinnias, which thrive in Portland's dry spells between frequent rain showers.
- Japanese beetles are likely to appear soon on succulent leaves of okra and summer squash; inspect plants early morning when they are most active.
- Powdery mildew can quickly coat basil, borage, and nasturtiums during our high-humidity mornings; water at the base only after 10 AM.
Watering this week
Water deeply at the base of plants in the morning to keep foliage dry and reduce disease risk during hot days.
Harvest watermelons when they produce a hollow sound upon tapping, indicating full ripeness.
Portland gardening questions
3When is the best time to harvest my cantaloupe and honeydew melons in Portland?
Harvest your melons soon when they emit a sweet aroma at the stem end, as our mild fall weather means they can rot on the vine if left too long. Check daily as fruit ripens rapidly during these warm days.
Can I still plant okra and watermelon now in August?
Yes, you can sow okra and watermelon seeds immediately since we are well past our March 1 frost date and soil is still warm enough for rapid germination. However, keep an eye on them as nights will eventually cool down by late September.
My basil plants are getting powdery mildew in the fog; how do I fix it without stopping harvest?
Prune off any heavily infected leaves and ensure you water at the soil level rather than overhead to reduce humidity around the foliage. A light misting of neem oil can help control the spread if caught early.
Other cities in zone 8b
12See the full zone 8b guide → · Plan your Portland garden in SproutGuide →