Planting calendar
March Planting Guide for Seattle, WA: Raised Beds, Containers & In-Ground Gardens
March in Seattle is a great time to start planting cool-season crops in raised beds, containers, and in-ground gardens. Focus on hardy vegetables and herbs that tolerate early spring conditions. Begin sowing seeds indoors for warm-season plants to transplant later.
Plant now (quick list)
lettuce, spinach, kale, peas, radishes, carrots, chard, onions (sets)
Plant now
- lettuce
- spinach
- kale
- peas
- radishes
- carrots
- chard
- onions (sets)
- potatoes
- broccoli seedlings
Start indoors
- tomatoes
- peppers
- eggplants
- basil
- cucumbers
- melons
- zucchini
- pumpkins
Avoid
- beans (direct sowing)
- corn
- sweet potatoes
- warm-season herbs like rosemary outdoors
- tender flowers like impatiens
Next 2 weeks
- harden off broccoli seedlings
- thin early radish and carrot seedlings
- continue sowing peas every 2 weeks for succession
- monitor soil moisture for raised beds and containers
- apply balanced fertilizer to established plants
FAQs
Can I plant tomatoes outdoors in March in Seattle?
No, tomatoes are frost-sensitive and should be started indoors in March and transplanted outdoors after the last frost, usually in late April or May.
Is it safe to plant peas directly in the ground now?
Yes, peas tolerate cool soil and can be sown directly in the ground in March in Seattle.
How often should I water containers during early spring?
Water containers when the top inch of soil feels dry, typically every 2-3 days, but adjust based on weather conditions.
Should I fertilize my raised bed soil before planting?
Yes, applying a balanced fertilizer or compost before planting helps provide nutrients for early spring crops.
When is the best time to transplant seedlings outdoors?
Transplant seedlings after the last expected frost date, usually late April to early May in Seattle, and harden them off for 7-10 days beforehand.
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