Planting calendar
August Planting Guide for Seattle Gardens: Raised Beds, Containers, and In-Ground
In August, Seattle gardeners can focus on planting cool-season crops and preparing for fall harvests. This is an ideal time to sow leafy greens, root vegetables, and start some seeds indoors for transplanting later. Whether you garden in raised beds, containers, or directly in the ground, timely planting now ensures a productive autumn garden.
Plant now (quick list)
spinach, lettuce, radishes, kale, beets, carrots, arugula, turnips
Plant now
- spinach
- lettuce
- radishes
- kale
- beets
- carrots
- arugula
- turnips
Start indoors
- broccoli
- cauliflower
- cabbage
- Brussels sprouts
- kohlrabi
- lettuce (for transplanting)
- chard
- herbs like parsley and cilantro
Avoid
- warm-season crops like tomatoes
- peppers
- eggplants
- beans
- corn
- melons
- squash
- cucumbers
Next 2 weeks
- direct sow more leafy greens for continuous harvest
- thin seedlings to prevent overcrowding
- water consistently to support new transplants
- add mulch to conserve moisture and suppress weeds
- monitor for pests like aphids and slugs
- start hardening off indoor seedlings for fall planting
- amend soil with compost for upcoming crops
- plan succession planting for late fall harvests
FAQs
Can I plant tomatoes in August in Seattle?
It's best to avoid planting tomatoes in August as the growing season is winding down and cooler temperatures may prevent fruit from ripening fully.
How do I protect my fall crops from early frosts?
Use row covers or cold frames to shield plants from frost, and consider planting in containers that can be moved indoors if needed.
Is it better to start seeds indoors or direct sow in August?
Cool-season crops like leafy greens can be direct sown, but brassicas often benefit from starting indoors to get a head start before transplanting.
How often should I water raised beds and containers in August?
Water deeply and regularly, typically every 2-3 days, but adjust based on rainfall and temperature to keep soil consistently moist but not waterlogged.
What soil amendments help late summer planting?
Incorporate compost or well-rotted manure to improve fertility and moisture retention, supporting healthy growth of fall crops.
Next steps
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