What to plant this week in Seattle, WA
Seattle gardeners in zone 9a are already deep into the growing season, with frost-free conditions established since early February. This week marks a critical window for harvesting your early beans and melons while simultaneously sowing warm-weather crops like okra and cucumbers that thrive in our mild maritime climate.
The next 7 days
Seattle, WAGrowing in Seattle right now
- Our heavy clay soils retain moisture well but drain poorly in low spots, so ensure raised beds or mounded hills are used for root vegetables to prevent waterlogging during our frequent spring rains.
- While daytime temperatures often reach the 70s, cool nights can slow germination; use row covers on new sowings like fennel and sunflowers until soil temps consistently stay above 65°F.
- Seattle's constant overcast sky delays maturity for heat-loving crops like cantaloupe and okra compared to inland zones, so prioritize high-yield varieties that mature quickly in our shorter summer window.
Sow this week
26 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- French Marigold
- Garden Verbena
- Lima Bean
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sweet Corn
- 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 to ensure a continuous harvest throughout the summer.
- Mulch newly planted crops with organic matter to retain soil moisture and keep roots cool during hot spells.
- Pinch back the tips of basil and oregano regularly to encourage bushier growth and prevent early flowering.
Pest & disease watch
- Watch for aphids clustering on the undersides of newly planted basil and nasturtiums, which thrive in our humid microclimates near water features.
- Slugs and snails are actively feeding on tender seedlings like edamame and shiso; apply organic copper tape or beer traps immediately as rain washes away natural predators.
Watering this week
Water deeply in the early morning to encourage deep root growth while minimizing evaporation losses.
Harvested okra pods should be picked daily when young to prevent them from becoming tough and fibrous quickly.
Seattle gardening questions
3When is the last chance to plant garlic for winter harvest in Seattle?
Since our average first frost arrives mid-December, you have until late October to sow hardneck garlic varieties before the ground freezes solid. Plant cloves 2 inches deep with the pointed end up to ensure strong root establishment.
Can I transplant tomato seedlings now or should I wait for more rain?
Do not transplant tomatoes this week; our cool, wet soil temperatures and high humidity increase the risk of damping-off disease. Wait until mid-June when soil warms above 60°F to reduce stress on these sensitive plants.
Which beans grow best in Seattle's short summer?
Focus on pole beans like Scarlet Runner or Bush Bean, as they produce continuously throughout our season unlike bush varieties that bolt quickly. Plant them now for a harvest window extending into August before the first light frosts.
Other cities in zone 9a
9See the full zone 9a guide → · Plan your Seattle garden in SproutGuide →