What to plant this week in Seattle, WA
Seattle gardeners in zone 9a are currently navigating a mild, rain-drenched week where frost risk has long passed since February 6th. With temperatures holding steady around the 20°F minimum and heavy spring rains continuing into December, this is an ideal time to sow warm-season crops like Bush Beans and Cucumber while your early harvests of Basil and Sweet Corn are ready to pick.
The next 7 days
Seattle, WAGrowing in Seattle right now
- Expect saturated soil from Pacific frontal systems; avoid working wet earth until drainage improves or use raised beds for root crops like Lima Bean.
- Heavy rain often washes away loose topsoil, so mulch heavily with straw or wood chips around young Zinnia and Sunflower plants to retain moisture and prevent erosion on slopes.
- High humidity creates a humid microclimate perfect for leafy greens like Malabar Spinach but requires vigilant monitoring to prevent fungal issues.
- Take advantage of the long daylight hours in late autumn/early winter to start succession planting for next spring, as frost dates don't arrive until mid-December.
Sow this week
34 crops- Basil
- Black-Eyed Susan
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Lima Bean
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- 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 now for a continuous summer supply.
- Mulch around newly transplanted Warm-Season crops like Zucchini to retain moisture and suppress weeds.
- Pinch back the tips of young Sunflowers to encourage bushier growth before they start flowering.
- Prepare soil beds with compost if you plan to sow Pumpkin or Winter Squash soon.
Pest & disease watch
- Aphids and spider mites are thriving in the humid, damp conditions common around Seattle this time of year, especially on soft-leaved plants like Fennel and Nasturtium.
- Slugs and snails remain highly active during cool, wet nights, frequently targeting young transplants and seedlings of Bush Bean and Pole Bean.
- Powdery mildew can develop quickly on susceptible varieties like Cucumber and Winter Squash when foliage stays wet for extended periods.
Watering this week
Water deeply in the early morning to minimize evaporation, especially as temperatures rise past 85°F.
Harvest Basil regularly by snipping leafy stems from the top to keep the plant producing new growth all summer long.
Seattle gardening questions
3When is the last chance to plant frost-sensitive crops before winter sets in?
Since your average first frost date here is December 15th, you have until mid-December to sow hardy annuals like Cosmos or Malabar Spinach that can tolerate light frosts, though warm-season beans and melons should be harvested well before then.
My Sweet Corn and Basil are ready now; how do I handle the harvest in such rainy weather?
Harvest your vegetables promptly to prevent rot from the constant moisture; use a tarp or cover your produce immediately after cutting it to keep it dry while you bring it inside for storage.
Can I plant Garlic again this week even though many other crops are listed for sowing?
While the current list highlights warm-season sowings, Garlic is uniquely suited for fall planting in Seattle and can be started now if the soil isn't frozen solid, as it requires a cold period to bulb properly before summer growth.
Other cities in zone 9a
9See the full zone 9a guide → · Plan your Seattle garden in SproutGuide →