📅 Seattle Planting Calendar
Month-by-month guide for USDA Zone 8b (Seattle / Puget Sound region). Last frost: ~April 15 · First frost: ~November 15
❄️ January
- • Plan your garden—order seeds from Territorial Seed Co (Cottage Grove, OR) or Uprising Seeds (Bellingham, WA)
- • Prune dormant fruit trees and roses on dry days
- • Start onion seeds indoors under grow lights
- • Clean and sharpen tools—oil wooden handles
- • Check on overwintering perennials under mulch
- • Browse nursery catalogs for spring-blooming shrubs and trees
- • Bring in potted rosemary and bay laurel if hard freeze is forecast
- • Force branches of forsythia, quince, or cherry indoors for early blooms
- • Test soil pH—PNW soil tends acidic, great for blueberries and rhododendrons
🌱 February
- • Direct sow: peas, fava beans, spinach, radishes (if soil is workable)
- • Start indoors: tomatoes, peppers, eggplant under grow lights
- • Prune blueberries, grapes, and ornamental grasses before new growth
- • Apply dormant spray to fruit trees for pest and disease prevention
- • Top-dress beds with compost—Cedar Grove compost is excellent locally
- • Start sweet pea seeds indoors (soak overnight first for faster germination)
- • Prune hydrangeas—remove dead wood only on mopheads (buds set on old wood)
- • Cut back ornamental grasses to 4–6 inches before new shoots emerge
- • Divide and transplant snowdrops and hellebores while in bloom
🌷 March
- • Direct sow: lettuce, carrots, beets, chard, kale, potatoes, radishes
- • Transplant: broccoli, cabbage, cauliflower starts outdoors
- • Start basil, cucumbers, and squash seeds indoors
- • Divide overgrown perennials: hostas, daylilies, echinacea, ornamental grasses
- • Plant bare-root fruit trees, berries, and roses—last chance before they leaf out
- • Start dahlia tubers in pots indoors for a head start on the season
- • Plant or transplant shrubs: rhododendrons, hydrangeas, lilacs, camellias
- • Cut back lavender to just above woody growth—never cut into old wood
- • Enjoy early blooms: crocus, daffodils, cherry blossoms at UW Quad
🌧️ April
- • Transplant tomato and pepper starts (after mid-month, with Wall-o-Water protection)
- • Direct sow: beans (after soil reaches 60°F), more lettuce and greens
- • Start squash and cucumber seeds indoors for May transplanting
- • Plant strawberries—Hood variety for PNW flavor
- • Apply organic slug bait (iron phosphate)—slugs are a PNW reality
- • Plant out perennials: echinacea, hostas, peonies, heather
- • Transplant sweet pea starts to the garden with trellis support
- • Fertilize rhododendrons and camellias after they finish blooming
- • Deadhead daffodils but leave foliage to die back naturally (feeds the bulb)
☀️ May
- • After last frost (~May 10): transplant tomatoes, peppers, squash, basil outdoors
- • Direct sow: beans, corn, cucumbers, summer squash, sunflowers
- • Mulch everything 2–3 inches deep to conserve moisture for summer
- • Set up drip irrigation if possible—you’ll need it Jul–Sep
- • Harden off all remaining seedlings before transplanting
- • Plant dahlia tubers and nasturtium seeds outdoors after last frost
- • Direct sow annual flowers: nasturtiums, sunflowers, cosmos, zinnias
- • Pinch back chrysanthemums for bushy growth and more fall blooms
- • Attend Tilth Alliance’s Edible Plant Sale—Seattle’s biggest plant event!
🌻 June
- • Succession plant: lettuce, beans, beets every 2–3 weeks
- • Harvest: peas, lettuce, radishes, strawberries, herbs
- • Side-dress tomatoes with compost or fish emulsion every 2 weeks
- • Stake and cage tomatoes before they flop—use sturdy supports
- • Watch for aphids—blast with water hose or introduce ladybugs
- • Deadhead roses, lavender, and other perennials to encourage reblooming
- • Prune spring-flowering shrubs (lilac, rhododendron) immediately after bloom
- • Begin deep watering schedule—Seattle’s dry season starts now
- • Enjoy peak blooms: lavender, peonies, sweet peas, rhododendrons
🍅 July
- • Harvest: first tomatoes, beans, zucchini, blueberries, cucumbers, raspberries
- • Plant fall crops: kale, broccoli, Brussels sprouts, cabbage starts
- • Direct sow: fall beets, carrots, lettuce, spinach for autumn harvest
- • Water consistently 1–2 inches/week—Seattle’s dry summers surprise newcomers!
- • Harvest garlic when lower 3–4 leaves brown—cure in shade for 2–4 weeks
- • Stake and tie dahlias as they grow tall—feed every 2 weeks with bloom fertilizer
- • Deadhead annuals and perennials regularly for continuous summer blooms
- • Take semi-hardwood cuttings of hydrangeas and lavender to propagate
- • Watch for powdery mildew on roses and squash—improve air circulation
🌾 August
- • Peak harvest: tomatoes, squash, beans, corn, berries, peppers, cucumbers
- • Direct sow overwintering crops: kale, spinach, chard, winter lettuce
- • Plant fall lettuce in succession every 2 weeks through mid-month
- • Start saving seeds from best-performing heirloom varieties
- • Enjoy the bounty! Preserve excess by canning, freezing, dehydrating, or sharing
- • Divide and transplant bearded iris (every 3–4 years for best bloom)
- • Order spring-blooming bulbs (tulips, daffodils, alliums) for October planting
- • Cut and dry lavender stems and hydrangea blooms for indoor arrangements
- • Continue deep watering trees and shrubs—they need it most during dry August
🍂 September
- • Harvest winter squash when stems are dry and corky—cure in sun 10–14 days
- • Plant garlic cloves (mid-Sep through Oct—top priority for PNW fall gardening)
- • Sow cover crops (crimson clover, winter rye, fava beans) in empty beds
- • Transplant fall starts: overwintering broccoli, cauliflower, Brussels sprouts
- • Begin putting the edible garden to bed—pull spent plants, add to compost
- • Plant trees, shrubs, and perennials—fall is the #1 planting season in PNW!
- • Divide hostas, daylilies, echinacea, and other overgrown perennials
- • Dig up dahlia tubers after first frost blackens foliage—store in cool, dark place
- • Overseed or repair bare lawn patches—fall rain will do the watering for you
🎃 October
- • Plant garlic cloves pointy-end up, 2″ deep, 6″ apart (top fall priority!)
- • Plant spring-blooming bulbs: tulips, daffodils, crocus, alliums, hyacinths
- • Mulch overwintering crops and perennials heavily with 3–4 inches of leaves or straw
- • Clean up fallen leaves—compost, make leaf mold, or use as mulch
- • Plant trees, shrubs, and perennials—roots establish over winter while tops rest
- • Move tender potted plants (figs, citrus) to sheltered spots or indoors
- • Cut back finished perennials but leave ornamental grasses for winter interest
- • Prepare rain garden plants for the wet season—clean debris from swales
- • Plant allium bulbs for dramatic spring globes—pair with peonies for stunning combos
🍃 November
- • Harvest: kale, chard, leeks, Brussels sprouts (sweeter after frost!)
- • Protect tender plants with row cover, cold frames, or cloches
- • Rake and compost leaves—or shred and use as mulch on beds
- • Clean and oil tools, drain hoses, winterize irrigation systems
- • Order seed catalogs and start planning next year’s garden layout
- • Enjoy late fall color: Japanese maples are at their spectacular peak now
- • Wrap young fig trees and tender shrubs with burlap for winter protection
- • Plant bare-root roses—available from nurseries now through March
- • Check stored dahlia tubers monthly—mist if shriveling, discard any that rot
🎄 December
- • Harvest overwintered greens (kale, chard, spinach) as needed for fresh meals
- • Plan next year’s garden layout—rotate crops, sketch beds, dream big
- • Browse seed catalogs: Territorial, Uprising, Adaptive Seeds, Nichols Garden Nursery
- • Give gardening gifts: seeds, quality tools, garden journal, nursery gift cards
- • Enjoy winter blooms: camellias, winter heather, witch hazel, hellebores
- • Force paperwhite narcissus and amaryllis bulbs indoors for holiday color
- • Protect outdoor containers from cracking—move glazed pots under cover
- • Walk the garden and note changes needed—dormant season reveals the garden’s bones
- • Rest, compost, and reflect—the garden is sleeping but planning never stops
💡 PNW Gardening Tips
- • Seattle's dry summers surprise newcomers — water consistently Jul–Sep
- • Slugs are a fact of life — organic slug bait (iron phosphate) is safe for pets
- • Fall is planting season for trees, shrubs, and perennials — roots establish over winter
- • Cover crops in empty beds prevent erosion during rainy winters
- • Buy local seeds from Territorial Seed, Uprising Seeds, or Adaptive Seeds for PNW-adapted varieties