Understanding Seattle's Unique Growing Environment
Seattle offers one of the best climates in America for container gardening - if you understand how to work with the rain and limited sun. Mild temperatures year-round mean you can grow something 12 months a year. The challenge isn't cold or heat - it's managing moisture and making the most of whatever sun you get. If you're just getting started, our complete guide to container gardening for beginners covers the fundamentals.
Seattle Gardening Challenges:
- Limited sunlight: Cloud cover October-May. Many balconies get 3-4 hours sun max, even south-facing.
- Excess moisture: 37 inches annual rain, mostly Oct-May. Overwatering and fungal diseases common. Learn proper watering techniques for containers.
- Poor drainage in rainy season: Containers can become waterlogged without proper drainage. See our guide to solving drainage problems.
- Slug paradise: Cool, wet conditions create perfect slug and snail habitat. Our pest control guide covers common garden pests.
- Slow plant growth: Cool temps (50-65°F much of year) mean slower maturation times.
- Vitamin D deficiency... for plants: Low light stress plants, especially shade-intolerant crops.
Seattle Gardening Advantages:
- Mild winters: Zone 8b/9a rarely freezes. Many crops overwinter successfully.
- Year-round growing: Cool-season crops thrive Oct-May. Plant something every month.
- No summer heat stress: 70-80°F summers perfect for cool-season crops. Lettuce grows all summer!
- Natural rainfall: Free watering Oct-May. Reduces summer water bills significantly.
- Excellent garden centers: City People's, Swansons, Sky Nursery, Molbak's
- Long summer days: 16 hours daylight in June compensates for cloud cover.
- Ideal for greens: Cool, moist climate = lettuce, kale, chard heaven
Best Plants for Seattle Containers
Success in Seattle means choosing shade-tolerant, cool-loving, moisture-resistant plants:
Leafy Greens (Absolute Best for Seattle)
Grows year-round in Seattle! Buttercrunch, Red Sails, Romaine. Plant every 2 weeks for continuous harvest using succession planting techniques.
Lacinato, Red Russian. Plant March-Sept. Harvest 10 months/year. Frost improves flavor.
Plant Sept-April. Grows through winter. Bolts less than other climates due to cool temps.
Peppery and fast (30 days). Plant year-round. Less prone to bolting in Seattle's cool climate.
Bright Lights for color. Plant spring or fall. Tolerates light frost. Gorgeous in containers.
Bok choy, mizuna, tatsoi. Perfect for Seattle. Cool-season specialists that don't bolt.
Cool-Season Vegetables (Spring & Fall Stars)
Plant March-April. Sugar Ann, Oregon Giant. Trellis on railing. Harvest May-June.
Transplant March-April or Aug-Sept. Mature better than hot climates. Need 5-gallon pots.
18-25 days. Plant March-Oct. French Breakfast, Cherry Belle. Fill gaps everywhere.
Short varieties (Chantenay, Danvers). Plant April-July. Harvest Sept-Nov. Need deep (12"+) pots.
Plant April-Aug. Detroit Dark Red. Both roots and greens edible. 60 days to harvest.
Plant spring, harvest fall-winter. Excellent overwintering crop. Frost improves flavor.
Herbs (Many Overwinter)
Biennial. Plant spring. Grows through winter. Harvest year-round until it flowers (year 2).
Plant Sept-May. Doesn't bolt in Seattle's cool temps like it does elsewhere. Year-round harvest possible.
Perennial. Survives Zone 8b winters easily. First harvest April, last in November. Divide every 3 years.
Perennial. Evergreen in Seattle. Harvest year-round. Protect in severe cold (below 20°F).
Perennial in Seattle! Bring indoors if temps drop below 15°F. Drought-tolerant for summer.
Invasive - grow in separate pot. Dies back in winter, returns spring. Spearmint, chocolate mint thrive.
Summer Vegetables (Need Full Sun Spots)
Stupice (52 days), Early Girl (52 days). Buy transplants late May. Need sunniest spot. Moderate yields. Watch for blossom end rot in wet conditions.
Better than tomatoes for Seattle. Transplant late May. Shishito, jalapeño, banana peppers.
Provider (50 days). Plant June. Mature Aug-Sept. More reliable than pole beans.
Zucchini, yellow squash. Plant June. One plant produces heavily July-Sept even in Seattle.
Wait until June when soil warms. Genovese or Thai. Grows slowly but steadily. Protection from rain helps. If leaves turn yellow, check our guide to fixing yellow basil leaves.
Bush varieties like Spacemaster. Plant early June. Trellis. Moderate success in Seattle.
Fruits & Berries
Rainier, Shuksan (PNW varieties). Plant spring. Produce June-July. Overwinter successfully.
Seattle is blueberry capital! Duke, Bluecrop. Need acidic soil. 15+ gallon pot. Perennial.
Heritage or Shortcake. 10+ gallon pot. Trellis needed. Vigorous. Fruit July-Aug.
Needs 500+ chill hours (Seattle provides this!). Gravenstein, Liberty. 15-20 gallon pot.
Seattle Planting Calendar
🌱 March-April (Spring Begins)
Plant outdoors: Peas, spinach, lettuce, kale, radishes, carrots (all cold-hardy)
Weather: Still cool (50-60°F) and rainy. Perfect for cool-season crops.
Note: No rush - season is long. Can start these crops through May.
🌿 May (Warming Up)
Plant: More lettuce, kale, chard, herbs (cilantro, parsley, chives)
Warning: Still too cool for tomatoes/peppers/basil. Wait until June!
Tip: Start hardening off tomato seedlings late May for June planting
☀️ June-July (Summer)
Plant now: Tomatoes, peppers, basil, beans, squash, cucumbers (finally!)
Buy transplants: Early June is prime time at nurseries
Still grow: Lettuce thrives in Seattle's cool summers. Continue succession planting.
Longest days: 16 hours daylight compensates for clouds
🌞 August (Peak Warmth)
Harvest: Tomatoes, peppers finally ripening. Beans, squash producing.
Plant fall crops: Mid-Aug is perfect for fall lettuce, spinach, kale, radishes
Watering: Driest month. Actually need to water containers regularly.
🍂 September-October (Glorious Fall)
Plant: Lettuce, spinach, arugula, garlic, kale for winter harvest
Weather: Perfect growing conditions. 60-70°F, increasing rain.
Harvest: Last tomatoes before frost (usually late Oct). Fall greens starting.
Best season: Many Seattle gardeners prefer fall to summer!
❄️ November-February (Mild Winter)
Keep growing: Kale, chard, parsley, thyme, leeks survive and produce
Protection: Cover on nights below 28°F (rare). Mostly just keep growing.
Indoor: Microgreens, herbs on windowsills with grow lights. See our winter indoor growing guide
Advantage: Most US gardeners can't grow anything. Seattle can!
Managing Seattle-Specific Challenges
☁️ Maximizing Limited Sunlight
- Track your sun: Observe balcony for 3 days. Where does sun hit? For how long? Design around this.
- South-facing is gold: South and west-facing balconies get most light. North/east are shadiest.
- Reflective surfaces: White walls, aluminum foil backing bounces light onto plants (15-20% increase)
- Choose shade-tolerant crops: Lettuce, spinach, kale, herbs need only 3-4 hours sun. Explore more options in our low-light apartment plants guide
- Save sunniest spots: Reserve full sun areas (6+ hours) for tomatoes, peppers only
- Grow lights: Supplement with LED grow lights for seed starting or winter herbs
💧 Managing Excess Rain & Moisture
- Drainage is critical: Multiple drainage holes (3-5 per pot). Elevate on pot feet or bricks.
- Well-draining soil: Mix 30-40% perlite into potting soil. Standard mixes too heavy for Seattle rain. Learn more in our complete container soil mix guide.
- Covered areas: Position moisture-sensitive plants (tomatoes, peppers, basil) under balcony overhangs
- Rain protection: Clear plastic rain shelter for tomatoes prevents fungal diseases
- Empty saucers: Don't let pots sit in water. Check saucers after heavy rain.
- Choose resistant plants: Lettuce, kale, peas love rain. Tomatoes hate it.
- Fungicide preventive: Spray susceptible plants with organic fungicide Oct-May. See our powdery mildew treatment guide for prevention tips.
🐌 Slug & Snail Control
- The enemy: Cool, wet Seattle is slug paradise. They'll destroy seedlings overnight.
- Copper tape: Wrap copper tape around pot rims. Slugs get electric shock, won't cross.
- Diatomaceous earth: Ring around plants. Microscopic sharp edges cut slug bodies.
- Beer traps: Shallow dishes of beer. Slugs attracted, fall in, drown. Replace weekly.
- Hand-picking: Go out with flashlight at night. Pick off slugs, drop in soapy water.
- Slug bait: Iron phosphate baits (Sluggo) are safe for pets/wildlife. Effective.
- Elevation: Slugs climb but prefer ground level. Elevated pots have fewer visitors.
🌡️ Dealing with Cool Temperatures
- Accept slower growth: Tomatoes take 80-90 days in Seattle vs 60-70 in California. Plan accordingly.
- Early varieties mandatory: Can't grow 80+ day tomatoes. Must use 50-60 day varieties.
- Black containers: Dark pots absorb heat, warm soil faster in spring. 5-10°F warmer than white pots.
- Against building walls: Buildings radiate heat. Place heat-loving plants against warm walls.
- Embrace cool-season crops: Lettuce, kale, peas, spinach are your strengths. Lean into them.
- Row covers: Lightweight fabric adds 4-6°F warmth for spring crops
Where to Buy Supplies in Seattle
Nurseries & Garden Centers
- • City People's Garden Store (multiple locations)
- • Swansons Nursery (North Seattle)
- • Sky Nursery (Shoreline)
- • Molbak's (Woodinville)
Big Box Stores
- • Home Depot (multiple locations)
- • Lowe's (multiple locations)
- • McLendon Hardware (local chain)
Farmers Markets (Seedlings)
- • University District Farmers Market
- • Ballard Farmers Market
- • Capitol Hill Farmers Market
- • West Seattle Farmers Market
Resources & Classes
- • Seattle Tilth (workshops, classes)
- • Seattle P-Patch Program (community gardens)
- • UW Botanic Gardens
- • WSU Extension King County
Get Your Seattle-Specific Garden Plan
Enter your Seattle zip code for a Zone 8b plan with shade-tolerant varieties and rain management strategies. Also check out container gardening guides for similar climates like Chicago and New York City.
Create Seattle Garden Plan