Seattle Transportation recommends low growing plants (less than 24” high) for traffic circles and planting strips within 30’ of an intersection. Other planting strip plants may reach a height of 36”. Trees should be pruned to provide visibility of oncoming traffic and the W-81 reflector sign. Rocks and wood or metal posts are NOT allowed in traffic calming devices within the street right-of-way.
THESE PLANTS ARE LISTED AS SUGGESTIONS ONLY. AVAILABILITY MAY VARY
PLANTS
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NORTHWEST GARDEN
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PERENNIAL GARDEN
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HERB GARDEN
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OTHER FUN PLANTS
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Trees
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Adirondack Crabapple (disease resistant)
Mt Ash
Dogwood ‘Eddies White Wonder’
Amelanchier (Serviceberry)
Washington Hawthorn
Others may be acceptable depending on site
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Flowering Cherry**
Flowering Pear
Goldenrain Tree
Jacquemontii Birch
Maple
Raywood Ash
Thornless Cockspur Hawthorn
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Ginkgo biloba
Honey Locust
Jackmontii Birch
Crabapple ‘Adirondack’
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Deciduous Magnolia
Evergreen Magnolia
Goldenrain Tree
Red Oak
Washington Palm Tree
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Shrubs
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Evergreen Azalea, dwarf (not drought tolerant)
Heathers & Heaths, various low growing varieties
Mahonia nervosa (low Oregon grape)
Dwarf Rhododendrons
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Mt Vernon Laurel
Dwarf Nandina
Potentilla fruticosa
Boxleaf Euonymous
‘Kobold’ Green Barberry
Forsythia ‘Bronxensis’
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Lavender
Rosemary (low forms)
Sage
Hebe glaucophylla
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Escallonia ‘Newport’ (not super drought tolerant)
Juniper ‘Blue carpet’
Spirea bumalda ‘Little Princess’
Ilex crenata ‘Helleri’
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Other Ornamentals
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Phormium ‘Jack Spratt’ & ‘Thumbelina’ (matures at or less than 2’ Tall)
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Blue Fescue
Penesetum orientale
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Alstroemeria (spreads)
Crocosmia ‘Kathleen’
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Perennials
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Astilbe, Campanula, Columbine, Coral bells, Dicentra, Geranium sanguineum, Penstemon, Sedum (dwarf varieties), Rockcress, Deer fern, Sword fern, Viola
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Asters, Coreopsis, Day lily,
Dianthus, Dwarf Shasta Daisy,
Helianthemum (Sunrose),
Iris sibirica
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Anthemis
Dusty Miller
Euphorbia
Sedum – many low growing ones
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Bergenia
Kniphofia ‘Little Maid’
Lily ‘Miss America’
Salvia x jamensis ‘San Takao’
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Ground Cover
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Epimedium, Fragaria, Kinnikinnick
Mahonia repens, Rubus calycinoides
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Bergenia crassifolia
Cottoneaster dammeri
Genista pilosa
Juniperus horizontalis
Liriope spicata
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Ajuga
Woolly & Creeping Thyme
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Raoulia autralis
Sedum & Sempervivum
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Bulbs, Corms, etc.
Supplied by Volunteers
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Anemone
Iris douglasiana
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Dutch Iris, Iris sibirica, Iris setosa, Daffodils, Crocus
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| THESE PLANTS ARE LISTED AS SUGGESTIONS ONLY. AVAILABILITY MAY VARY For a list of recommended trees, look at our web site: http://www.ci.seattle.wa.us/td/landserv.asp **Flowering Cherries are not recommended at this time because of their susceptibility to the Cherry Bark Tortrix, a moth that damages these trees. Low growing, drought tolerant, and encourages butterflies or hummingbirds Latin Name | Common Name | Flower Color | Size (height x spread)** | Agastache var | Wild Hyssop | Blues and Orange varieties | Select low growing varieties** | Aquilegia species hb | Columbine | Various colors | 2 to 3 feet** | | | Butterfly Weed | Orange, sometimes Yellow | 18 “ tall x 18” wide | Aster x frikartii ‘Monch’ bf | Aster | Lavender-blue | 30” tall x 24” wide | Aster novi-belgi ‘Alert’ bf | | | | Echinacea purpurea ‘White Swan’ bf | Coneflower | White | 24” to 30” tall and 24” wide | Eriogonum umbellatum bf hb | Sulfur buckwheat | Shades of Yellow | 10” tall x 18” wide | Gallardia grandiflora ‘Goblin’ bf | | | 12” tall x 15” wide | | | | | | Heuchera sanguinea hb | Coral Bells | Pink and Red varieties | 18” to 24” tall, 15” wide | | | Lavender | Varieties vary - white to deep purple for flowers, silver to dark green for leaves | 10” to 3 feet tall and as wide depending on the variety ** | Liatris punctata hb | Gayfeather | Purple | 32” tall x 24” wide ** | Lysimachia clethroides bf | | | | Monarda x ‘Petite Delight’ | Bee balm | Light Lavender-Rose flowers with glossy green foliage | 15” tall x 24” wide | | | Penstemon | Various colors | From 8” to 3 feet tall ** | Salvia varieties hb bf | | Humming birds really go for the reds | 2 to 3 feet tall, ** | Scabiosa x hybrids bf | Pincushion Flower | Pink or Blue | 12” tall x 15” wide | Sedum telephium ‘Arthur Breanch’ bf | Stonecrop | | 15-18” tall x 12” wide | Sedum telephium ‘Autumn Joy’ | Showy Stonecrop | Flowers start pink and turn bronze | 15-18” tall x 15” wide | Solidago ‘Golden Fleece’, ‘Fireworks’ bf | Dwarf Goldenrod | Golden Yellow | 15” tall x 24” wide | Verbena varieties bf | | | | Veronica varieties bf | Speedwell | Varieties range from White, Pink, Blue, Purple | ** Select varieties maturing at less than 24” tall for planting in Traffic Circles | This is a sample listing of plants not suited for planting within 30’ of an intersection because they get too tall, bushy, or are considered to be invasive.
Bearded Iris, tall forms Butterfly bush
Bamboo, except low ground cover types
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Let us know if you see examples of creative and appropriate right-of-way plantings we can highlight on future lists.
ardoon, Globe Thistle & Artichoke
Fennel
Tall Grasses incl. Pampas grass
Holly
Ivy of any ilk!! (There is no benign ivy)
Lavatera Lilac
New Zealand Flax (unless dwarf varieties that mature less than 24”)
Rhododendron, except low dwarf varieties
Roses – shrub and climbing
Shrubs whose growth exceeds 2-1/2 feet tall and that need continuous shearing such as: Photinia, Viburnum laurestinus & ‘Spring Bouquet’
Silver Lace Vine Staghorn Sumac
Frequently asked Traffic Circle/ Street Right-of-Way Questions:
How do I dispose of garbage and clean green?
Typically, volunteers use their own garbage and green waste containers. If you have an abundance of material, contact Liz Ellis at 684-5008 to talk about getting a free dump pass.
How do I get water out to the garden?
First, ask a neighbor at one of the corners if you can use their water. If not, five gallon buckets or a garbage can in the back of a truck could get you through a few weeks of hot, dry weather. Water new trees with at least five gallons for every diameter inch of tree trunk once a week or as often as necessary.
My traffic circle garden needs mulch. Can the City help out?
The best source of mulch is free wood chips from a Tree Service company listed in the Yellow Pages. Otherwise beauty bark or compost can be used.
I would like to decorate my circle garden. Are rocks or sculpture allowed?
Only plants and an approved W-81 center sign are allowed in circles.
Are there any other special considerations to gardening in the street right of way?
Yes. Please only select plants that will mature at 2-feet tall to plant within 30' of the intersection. Trees should start out with a trunk diameter of 1-1/2 inches and be thinned if necessary so that the W-81 reflector sign is visible.
Please be safe! You are gardening in an area where drivers may not be paying close attention. Wear visible clothes. Liz can provide safety vests if necessary. Face oncoming traffic. Keep yourself and your tools off the roadway.
You'll find many other folks will be very supportive of your good work. Encourage them to join you, if not today perhaps another time!
Please don't hesitate to ask for help!
Prepared by Liz Ellis, updated 8/02. Please call SDOT Urban Forestry 684-8733 with suggestions for adding other plants to this list.
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