What to plant this week in Seattle, WA
Seattle gardeners in zone 9a are currently navigating the tail end of winter's chill with a minimum temperature hovering near 20°F, though the average last frost date has already passed for mid-February. This week marks the critical transition from cold frames to outdoor planting as you can safely sow warm-season seeds like Bush Beans and Zinnia directly into your Pacific Northwest soil.
The next 7 days
Seattle, WAGrowing in Seattle right now
- Avoid transplanting any seedlings this week; the current 'transplant_now' list is empty, so start everything from scratch or wait for warmer soil temperatures later in spring.
- Focus on starting heat-loving crops immediately: sow Cleome, Cucumber, and Yellow Summer Squash now to get a jumpstart before our frequent summer rain showers arrive.
- Take advantage of the long growing season extending until mid-December by planning your fall harvest of Winter Squash and Pumpkins for late autumn picking.
- Monitor your low-lying areas carefully as Seattle's microclimates often hold frost longer than higher elevations, despite the zone 9a classification.
Sow this week
18 crops- Basil
- Borage
- Bush Bean
- Cleome (Spider Flower)
- Cucumber
- French Marigold
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- 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 every two weeks for a continuous harvest throughout the summer heat.
- Mulch around newly transplanted squash and pumpkins to retain moisture and suppress weeds as temperatures rise.
- Pinch back the tops of basil plants regularly to encourage bushier growth and prevent flowering.
Pest & disease watch
- Watch for early spring aphids on new Basil and Shiso seedlings as they emerge from cold protection.
- Inspect French Marigolds and Nasturtiums closely for spider mites which can become active during our dry spells in late April/early May.
- Keep an eye out for cutworms on young Pole Bean and Scarlet Runner Bean starts once night temperatures consistently rise above 50°F.
Watering this week
Water deeply in the early morning to help plants withstand afternoon heat while minimizing evaporation losses.
Harvest watermelon and cantaloupe regularly to signal the plant to continue producing fruit rather than stopping growth.
Seattle gardening questions
3Can I transplant my indoor tomato or pepper seedlings outside this week?
No, do not attempt to transplant any plants right now as the official list for Seattle indicates zero items are safe to move outdoors yet. Wait until soil temperatures consistently stay above 50°F and the threat of a sudden freeze drops significantly later in spring.
What warm-weather crops should I sow directly into my Seattle garden bed today?
You can immediately plant heat-loving varieties such as Cucumber, Okra, Yellow Summer Squash, and Zucchini since they thrive once our winter chill subsides. Also, don't miss your window to start Pole Beans, Bush Beans, or Shiso if you haven't already.
When should I expect my Garlic harvest in the Seattle area?
With an average first frost date around mid-December, plan to lift your Garlic crop soon as it begins to mature and dry out naturally. Check for signs of curing readiness like yellowing leaves, but ensure you don't leave them out too long given our damp late-autumn weather.
Other cities in zone 9a
9See the full zone 9a guide → · Plan your Seattle garden in SproutGuide →