What to plant this week in Portland, ME
With average last frost dates around April 21, Portland gardeners are now in the peak harvest window for warm-season crops like zucchini and bush beans, while outdoor temperatures remain cool enough to avoid shocking transplants. This week marks the transition from spring cleanup to aggressive harvesting, as days lengthen toward the October 17 first frost that will soon end the growing season.
The next 7 days
Portland, MEGrowing in Portland right now
- Portland's notorious 'New England mud' can waterlog heavy clay soils in low-lying areas; ensure raised beds have excellent drainage before planting late sowings like edamame or malabar spinach.
- Coastal fog and sea breeze create a microclimate that delays soil warming by several weeks compared to inland Maine, so mulch heavily to retain heat for garlic and parsnips stored over winter.
- Wind damage is common in the Portland metro area; stake tall crops like sunflowers, pole beans, and scarlet runner beans immediately after they reach 12 inches in height.
- Soil pH tends to be acidic across much of Cumberland County; test your soil before adding lime for brassicas or legumes if you plan to replant these next season.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
45 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and sweet corn every two weeks for continuous harvests through summer.
- Pinch back the tips of basil and okra to encourage bushier growth rather than flowering too early.
- Add a thin layer of straw or shredded leaves around heavy feeders like pumpkins and squash to retain moisture.
Pest & disease watch
- Late-season aphids often infest the undersides of basil, zinnia, and cosmos leaves in Portland's humid summers; rinse them off with a strong jet of water early in the morning.
- Squash vine borers frequently attack zucchini, yellow summer squash, and pumpkin vines once flowers appear; inspect stems for sawdust-like frass and remove affected plants immediately to prevent spread.
- Japanese beetles are active now on sunflowers, roses, and ornamental sweet potato vines; hand-pick them off in the early morning when they are sluggish.
Watering this week
Provide about 1 to 2 inches of water per week, applying it deeply in the morning to reduce evaporation and disease risk.
Harvest zucchini and summer squash early in the day when they are most tender and flavorful for your table.
Portland gardening questions
3Can I still start cold-hardy crops like parsnips or garlic outside right now?
Yes, although your zone 6a minimum of -10°F means you need to harvest these before a hard freeze, late sowings can be done in protected spots if the ground isn't frozen solid.
My zucchini and yellow summer squash are wilting; what is causing it?
In Portland's humid climate, this is often a sign of squash vine borer damage or excessive water stress; check for small holes in stems and ensure you aren't overwatering saturated clay soils.
When should I stop harvesting basil and bush beans before the first frost on Oct 17?
Cut back all warm-season annuals like basil, cosmos, and bush beans within two weeks of October 17 to allow plants to die back naturally or be pulled up cleanly.
Other cities in zone 6a
12See the full zone 6a guide → · Plan your Portland garden in SproutGuide →