Planting calendar
August Planting Guide for Seattle, WA: Raised Beds, Containers & In-Ground Gardens
In August in Seattle, focus on planting cool-season crops and preparing for fall harvests in raised beds, containers, and in-ground gardens. This is a great time to sow leafy greens, root vegetables, and herbs that thrive in cooler weather. Avoid heat-sensitive plants and start planning your fall garden now.
Plant now (quick list)
lettuce, spinach, kale, radishes, carrots, beets, Swiss chard, broccoli
Plant now
- lettuce
- spinach
- kale
- radishes
- carrots
- beets
- Swiss chard
- broccoli
- cauliflower
- parsley
Start indoors
- cabbage
- brussels sprouts
- collard greens
- kohlrabi
- celery
- leeks
- onion sets
- herbs (cilantro, dill)
- winter greens
- mustard greens
Avoid
- tomatoes
- peppers
- eggplants
- beans
- corn
- melons
- cucumbers
- summer squash
- basil
- tender annuals
Next 2 weeks
- direct sow fall root crops
- transplant cool-season seedlings
- mulch to retain soil moisture
- monitor for pests like aphids
- water consistently during dry spells
- thin seedlings for better growth
- start composting garden waste
- prune summer crops to encourage airflow
- prepare soil for fall planting
- plan crop rotation for next season
FAQs
Can I plant tomatoes in August in Seattle?
August is generally too late to start tomatoes in Seattle due to the shorter growing season and cooler temperatures approaching. It's best to focus on cool-season crops now.
How often should I water raised beds in August?
Water raised beds deeply about 2-3 times per week, adjusting for rainfall and temperature to keep soil consistently moist but not waterlogged.
Are containers suitable for fall crops in Seattle?
Yes, containers work well for cool-season crops like lettuce, spinach, and herbs, allowing you to extend your growing season and manage soil conditions easily.
What soil preparation is recommended before planting fall vegetables?
Amend soil with compost or organic matter to improve fertility and drainage, and ensure the soil is loose and well-aerated for root development.
Should I protect seedlings from early frosts in late August?
While frosts are unlikely in August, it's good practice to have frost protection like row covers ready for September as temperatures begin to drop.
Next steps
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