A Washington Native Formal Shade Garden

Washington Native Formal Shade Garden

Here is a formal shade garden, for Seattle & the Pacific Northwest Coast, using native plants.  The use of native plants has steadily increased in Seattle to the point where most nurseries now stock a fairly wide variety.  While it may be that I have been reading too many European garden blogs, it seems that formal gardens are also becoming more popular.  In any case, there is no need to use native plants only in wild gardens.  If your taste is for symmetry, you can achieve this with native plants.  

Both deciduous & evergreen plants are used in this garden.  Quercus garryana (Garry Oak) is the center of this garden.  It slowly grows to be a large & spreading deciduous tree.  Two sides of the garden are lined with the much smaller Acer circinatum (Vine Maple) which are very colorful in fall.  The most interesting feature of this garden is a double row of Sambucus racemosa (Red Elderberry).  Reaching 18 feet in height, the arching canes will meet over head at the center of the walks, forming a pleached allee.  Some lower branches may need to be removed for passage.  Vaccinium ovatum (Evergreen Huckleberry) can be pruned into relatively uniform hedges.  It is best not to clip them severely.  Blechnum spicant (Deer Fern) is an evergreen perennial lining the walks.  Space these about 18 inches apart.  You will need to choose at least 1 additional groundcover to spread throughout the area behind them.  Oxalis oregana (Redwood Sorrel) &/or Fragaria vesca (Woodland Strawberry) would give the most effective coverage.  Specific shrubs, perennials & groundcovers are indicated.  Use the additional perennials & groundcovers to fill empty spaces.  

The main entry walk is 4 feet wide.  Secondary walks are 3 feet wide.  You can pave these in brick, stone or concrete.  Use mortar, or the cracks will be invaded by plants.  The entire garden is 40 feet by 30 feet across.  Seattle lots are usually 40 or 50 feet wide.  If your lot is 50 feet wide, you can add 2 more rows of Acer circinatum (Vine Maple) along the sides.  Because this plan is symmetrical, solar orientation won’t matter.  This garden would be best in a shaded area.  The trees & shrubs are tolerant of sun & shade.  They will eventually grow to shade the woodland plants beneath them.  If you have room, you can add other gardens beyond this.  A bosque or thicket would work well, especially along property lines.  Remove the benches & continue the walks into adjacent spaces. 

Washington Native Formal Shade Garden Plan

Trees
AC = Acer circinatum (Vine Maple): total # 16
G = Quercus garryana (Garry Oak): total # 1
Shrubs
PH = Physocarpus capitatus (Ninebark): total # 4
R = Rhododendron macrophyllum: total # 12, evergreen
S = Sambucus racemosa (Red Elderberry): total # 8
V = Vaccinium ovatum (Evergreen Huckleberry): total # 12, evergreen
Perennials
AR = Aruncus dioicus (Goat’s Beard): total # 4
B = Blechnum spicant (Deer Fern): total # 72, evergreen
E = Erythronium oregonum (Fawn Lily): total # 8
P = Polystichum munitum (Sword Fern): total # 12, evergreen
TE = Tellima grandiflora (Fringecup): total # 16, evergreen
TR = Trillium ovatum (Wakerobin): total # 4
Groundcovers
A = Asarum caudatum (Wild Ginger): total # 8, evergreen
D = Dicentra formosa (Bleeding Heart): total # 12

Additional Perennials & Groundcovers
Achlys triphylla (Vanilla Leaf)
Cornus canadensis (Bunchberry): evergreen
Corydalis scouleri (Scouler's Corydalis)
Disporum hookeri (Hooker’s Fairybells)
Fragaria vesca (Woodland Strawberry): will spread throughout, evergreen
Heuchera glabra, Heuchera micrantha (Alum Root): evergreen
Maianthemum dilatatum (False Lily of the Valley): will spread throughout
Oxalis oregana (Redwood Sorrel): will spread throughout
Smilacina stellata (Starry False Solomon’s Seal): will spread throughout
Tiarella trifoliata (Foamflower): evergreen
Tolmiea menziesii (Piggyback Plant): evergreen
Vancouveria hexandra (Inside-out Flower)

To learn more about these plants read Plants of the Pacific Northwest Coast by Pojar & MacKinnon, or visit the Washington Native Plant Society website.

Pacific Northwest Dry Forest Garden

Arbutus unedo October 2010

Pinus monticola August 2008

Mahonia repens July 2010

Trillium ovatum March 2010

 Ribes sanguineum March 2010

Unless you have very many acres, this garden would more accurately be called a bosque, than a forest.  A bosque is a grove of trees, either in nature, or in landscape design.  I’m not sure how the word crept into landscaping.  It is a Spanish word meaning forest in the larger sense, as in the bosque amazonico, the Amazon Rain Forest.  In American landscape design, the word is pronounced ‘bosk,’ while in Spanish it has 2 syllables.  The French use the word ‘bosquet’ to describe a grove, usually contrived.  There are famous bosquets at the château de Versailles. 

This garden (or bosque) is designed entirely with plants from dry forests of the coastal Pacific Northwest, although some also grow in moist forests.  Plant this garden in sun with some slope (so that is sure to drain) or on ground that is already known to be dry.  The understory (everything but the trees) will grow in shade.  The trees want sun.  This is intended to be a garden of light, dappled shade.  Don’t plant the trees too close together.  Arbutus menziesii (Madrona) does not form a dense canopy.  Pinus ponderosa (Ponderosa Pine) is an open & slender tree.  Thuja plicata ‘Fastigiata’ (Hogan Cedar) is a columnar form of Western Red Cedar.  Pinus monticola (Western White Pine) & Quercus garryana (Garry Oak) are more spreading.  Use fewer of them, spaced widely apart.   This garden won’t need irrigation beyond the 1st few summers.  

To read more about these plants, get a copy of Plants of the Pacific Northwest Coast by Jim Pojar & Andy MacKinnon.

Pacific Northwest Dry Forest Garden Plant List
Trees
Acer circinatum (Vine Maple)
Amelanchier alnifolia (Saskatoon)
Arbutus menziesii (Madrona)
Pinus monticola (Western White Pine) Pinus ponderosa (Ponderosa Pine)
Quercus garryana (Garry Oak)
Thuja plicata ‘Fastigiata’ (Hogan Cedar)

Shrubs
Gaultheria shallon (Salal)
Mahonia aquifolium (Oregon Grape) Mahonia nervosa, Mahonia repens
Holodiscus discolor (Oceanspray)
Juniperus communis (Common Juniper)
Oemleria cerasiformis (Indian Plum)
Philadelphus lewisii (Mock Orange)
Rhododendron macrophyllum (Pacific Rhododendron)
Ribes sanguineum (Flowering Currant)
Rosa gymnocarpa (Dwarf Rose)
Symphoricarpos albus (Snowberry)

Vaccinium ovatum (Evergreen Currant)

Perennials

Achlys triphylla (Vanilla Leaf)

Allium cernuum (Nodding Onion)

Erythronium oregonum (Fawn Lily)

Festuca idahoensis (Idaho Fescue)

Lilium columbianum (Tiger Lily)

Polystichum munitum (Western Sword Fern)

Tellima grandiflora (Fringecup)

Trillium ovatum (Wake Robin)

Viola adunca (Early Blue Violet)

Groundcovers & Trailers

Arctostaphylos uva-ursi (Kinnikinnick)

Dicentra formosa (Bleeding Heart)

Fragaria vesca (Woodland Strawberry)

Lonicera hispidula (Hairy Honeysuckle)

Maianthemum dilatatum (False Lily of the Valley)

Smilacina stellata (aka Maianthemum stellatum)

Pacific Northwest Dry Forest Garden Plan

Trees

ACE = Acer circinatum (Vine Maple)

AME = Amelanchier alnifolia (Saskatoon)

ARB = Arbutus menziesii (Madrona)

PINE = Pinus ponderosa (Ponderosa Pine)

Shrubs

GAU = Gaultheria shallon (Salal)

MAH = Mahonia aquifolium (Oregon Grape)

HOL = Holodiscus discolor (Oceanspray)

PHI = Philadelphus lewisii (Mock Orange)

RHO = Rhododendron macrophyllum (Pacific Rhododendron)

RIB = Ribes sanguineum (Flowering Currant)

VAC = Vaccinium ovatum (Evergreen Currant)

Perennials

ACH = Achlys triphylla (Vanilla Leaf)

ALL = Allium cernuum (Nodding Onion)

ERY = Erythronium oregonum (Fawn Lily)

LIL = Lilium columbianum (Tiger Lily)

POL = Polystichum munitum (Western Sword Fern)

TEL = Tellima grandiflora (Fringecup)

TRI = Trillium ovatum (Wake Robin)

VIO = Viola adunca (Early Blue Violet)

Groundcovers & Trailers

ARC = Arctostaphylos uva-ursi (Kinnikinnick)

DIC = Dicentra formosa (Bleeding Heart)

SMI = Smilacina stellata (aka Maianthemum stellatum)

The Heathland Garden

Phlomis italica October 2010

Digitalis obscura June 2009

Allium karataviense May 2010

Lithocarpus densiflora var. echinoides October 2010

Calluna vulgaris 'Wickwar Flame' & Hebe x pimeleoides 'Quicksilver' October 2010

Hebe ochracea October 2010

Thymus pseudolanuginosis October 2010

Arctostaphylos columbiana (foreground) & Erica arborea 'Estrella Gold' May 2010

The Heathland Garden is a shrubby landscape, reminiscent of the moorlands of England, the heathlands of Scotland, & the alpine shrublands of New Zealand.  In addition to heath (Erica) & heather (Calluna), I have chosen xeric plants from the maquis shrubland of the Mediterranean Basin, plus some xeric plants from the Pacific Northwest.  The Heathland Garden combines plants from all of these places to form a dense tapestry of low shrubs & perennials, enclosed by a few taller shrubs.  This is a colorful garden, with blue-gray & yellow-gold foliage year round & perennial flowers in season.  Although it is not a highly xeric garden, it will only need occasional irrigation during Seattle summers.  I've found that Calluna & Hebe cannot go entirely without summer irrigation.  This garden must be planted in full sun.

Plan for the Heathland Garden

Heathland Garden Plant List
Shrubs
AC = Arctostaphylos columbiana (Hairy Manzanita)
AP = Arctostaphylos ‘Pacific Mist’ (Manzanita)
BRA = Brachyglottis monroi (aka Senecio monroi)
CAL = Calluna vulgaris ‘Wickwar Flame’ (Heather)
DAB = Daboecia cantabrica (Irish Heath)
EA = Erica arborea ‘Estrella Gold’ (Tree Heath)
HO = Hebe ochracea
HP = Hebe x pimeleoides ‘Quicksilver’
HT = Hebe topiaria
LIT = Lithocarpus densiflorus var. echinoides (Dwarf Tanoak)
OLE = Olearia x mollis
PHL = Phlomis italica
VAC = Vaccinium ovatum (Evergreen Huckleberry)

Perennials
ALC = Alchemilla mollis (Lady's Mantle)
ALL = Allium karataviense
CAM = Camassia quamash (Camas)
CRO = Crocus sieberi ‘Firefly’
DIG = Digitalis obscura (Foxglove)
ERI = Erigeron glaucus (Beach Aster)
EUP = Euphorbia rigida
HEL = Helleborus argutifolius (Corsican Hellebore)
IRI = Iris tenax

Groundcovers
HYP = Hypericum cerastoides (St John's Wort)
SED = Sedum ‘Vera Jameson’
THY = Thymus pseudolanuginosus (Woolly Thyme)

Allow Hebe x pimeleoides ‘Quicksilver’ to interweave with Calluna vulgaris ‘Wickwar Flame’ & Daboecia cantabrica.  In general, there should be very little need for pruning iin this garden.

The Dryland Garden

Echinocereus reichenbachii in Seattle June 2009

Yucca harrimaniae in Seattle August 2008

Sedum palmeri in Seattle December 2009

Tulipa turkestanica in Seattle March 2010

 Lewisia cotyledon in Seattle May 2010

Drylands are ecosystems with limited water, including scrublands, shrublands, grasslands, savannas, semi-deserts & true deserts.  A true desert garden is impossible in Seattle.  But you can give the impression of desert-like landscapes with carefully chosen plants, a very spare planting design, & plenty of rock & gravel.  This type of xeric garden is excellent for south or west-facing slopes, because it requires little or no irrigation.  If you’ve ever walked in a desert, you were probably surprised by the richness of the plant life.  There are some relatively barren deserts worldwide.  But the deserts of North America are filled with cactus, shrubs & small trees, perennial & annual wildflowers & grasses.  Below are images of natural drylands I have visited.  My ideas for the dryland garden are a synthesis of these landscapes & others I have seen.

 Joshua Tree National Park in California March 2009

Warm Springs Indian Reservation in Oregon September 1999

Frenchman Coulee in Washington June 2010

Cactus are nearly impossible to grow in Seattle.  I grow Echinocereus reichenbachii (Claret Cup Cactus) against the south side of a large stone, the only cactus that has worked for me.  Agave are somewhat less difficult.  I’ve tried at least a dozen, had success with Agave palmeri, Agave parryi var. huachucensis & Agave toumeyana var. bella. Yucca are similar to Agave & closely related.  Yucca filamentosa is widely grown in Seattle.  Native to the southeastern US, it tolerates dryness & moisture.  Western dryland Yucca that have grown well for me are Yucca harrimaniae, Yucca kanabensis, Yucca glauca, Yucca neomexicana & Yucca schottii.  I was amazed to find that Yucca whipplei, which grows in the very dry mountains near Los Angeles, grew to 4 feet  from a mere 6 inches in just 4 years.  It is both striking & alarming with its needle-tipped, sword-like leaves.  Plant Agave & Yucca well away from paths.  Agave, cactus & dryland Yucca should be grown in a raised area of gravelly & rocky soil.  Other successful succulent plants are Lewisia cotyledon & many Sedum.

I saw scrub oak growing in the Mojave Desert.  Scrub oaks include Quercus berberidifolia, Quercus john-tuckeri & Quercus vaccinifolia.  Shrubby pines such as Pinus edulis also grow in drylands.  A well-pruned Swiss Mountain Pine (Pinus mugo) will have a similar appearance.  Other dryland shrubs include manzanita & juniper.  You must to prune juniper, manzanita, oak & pine to give them a dryland appearance. To mimic sagebrush, use shrubs with gray foliage such as Brachyglottis munroi, Helichrysum splendidum & Santolina chamaecyparissus.  Rosa glauca & Rosa sericea var. pteracantha (with tall, thorny canes) give the impression of desert plants, especially in winter:

Wildflowers & grasses are always found in western drylands. Festuca idahoensis is a common grass from drylands of the Pacific Northwest & California.  It also grows west of the Cascade Mountains.  Try grasses with blue foliage such as Festuca ovina ‘Elijah Blue’ & Helictotrichon sempervirens, or with bronze foliage such as Carex comans ‘Bronze’ & Carex tenuiculmis ‘Cappucino’ .  For flowers use Achillea, Anthemis tinctoria, Erigeron, Penstemon x mexicali & Zauschneria californica.  Bulbs native to the western US are Calochortus & Triteleia.  Certain species tulips will also fit into this garden, although they are wildflowers from central Asian drylands.

Dry Garden Plant List

Succulents
Agave palmeri, Agave parryi var. huachucensis, Agave toumeyana var. bella
Echinocereus reichenbachii (Claret Cup Cactus)
Hesperaloe parviflora (Red Yucca)
Lewisia tweedyi, Lewisia cotyledon
Nolina nelsonii, Nolina parryi
Sedum divergens, Sedum oreganum, Sedum obtusatum, Sedum oregonense, Sedum palmeri, Sedum spathulifolium
Yucca filamentosa, Yucca harrimaniae (aka Yucca nana) Yucca kanabensis, Yucca neomexicana, Yucca glauca, Yucca schottii, Yucca whipplei

Shrubs & Small Trees
Arctostaphylos columbiana (Hairy Manzanita) Arctostaphylos bakeri, Arctostaphylos densiflora (Vine Hill Manzanita)
Brachyglottis monroi
Calluna vulgaris ‘Kerstin’, Calluna vulgaris ‘Silver Knight’
Eriogonum umbellatum (Sulfur Buckwheat)
Helichrysum italicum, Helichrysum splendidum, Helichrysum tianshanicum
Juniperus californica, Juniperus squamata ‘Blue Star’, Juniperus squamata ‘Loderi’
Lithocarpus densiflorus var. echinoides (Dwarf Tanbark Oak)
Mahonia fremontii (Desert Holly) Mahonia pinnata
Penstemon pinifolius (Pineleaf Beardtongue)
Pinus aristata (Bristlecone Pine) Pinus edulis (Pinyon Pine) Pinus monophylla (Singleleaf Pinyon) Pinus mugo (Swiss Mountain Pine) Pinus quadrifolia (Parry Pinyon)
Quercus berberidifolia (Scrub Oak) Quercus gambelii (Gambel Oak) Quercus john-tuckeri (John Tucker Oak) Quercus vaccinifolia (Huckleberry Oak)
Rosa glauca, Rosa sericea var. pteracantha
Santolina chamaecyparissus (Lavender Cotton)

Perennials & Grasses
Achillea ageratifolia, Achillea clavennae, Achillea kellereri, Achillea serbica, Achillea tomentosa (Yarrow)
Anthemis tinctoria (Marguerite Daisy)
Briza media (Rattlesnake Grass)
Calochortus superbus, Calochortus venustus (Mariposa Lilies)
Carex comans ‘Bronze’ (New Zealand Sedge) Carex tenuiculmis ‘Cappuccino’
Coreopsis verticillata (Tickseed)
Deschampsia flexuosa (Crinkled Hairgrass)
Erigeron glaucus (Beach Aster) Erigeron karvinskianus (Santa Barbara Daisy) Erigeron lineraris (Desert Yellow Fleabane)
Eryngium variifolium (Moroccan Sea Holly) Eryngium yuccifolium (Rattlesnake Master)
Eschscholzia californica (California Poppy)
Festuca idahoensis, Festuca ovina ‘Elijah Blue’ (Fescues)
Helictotrichon sempervirens (Blue Oat Grass)
Pennisetum alopecuroides ‘Hameln’ (Fountain Grass)
Penstemon x mexicali (Beardtongue)
Triteleia laxa ‘Queen Fabiolia’ (aka Brodiaea ‘Queen Fabiola’)
Tulipa dasystemon, Tulipa saxatilis, Tulipa turkestanica (Species Tulips)
Zauschneria californica (California Fuchsia) Zauschneria latifolia

Groundcovers & Trailers
Arctostaphylos x media, Arctostaphylos nevadensis (Pinemat Manzanita) Arctostaphylos nummularia
Ceanothus griseus var. horizontalis (Carmel Creeper)

Cerastium tomentosum (Snow-in-Summer) 
Hirpicium armerioides (Mat Daisy)
Juniperus communis ‘Green Carpet’, Juniperus conferta (Shore Juniper)

  

Plan for a Dryland Garden
This garden must be very well-drained.  It is best on south & west-facing slopes, in full sun.  The center area can be a raised bed enclosed with a stone wall.

Shrubs & Small Trees

AC = Arctostaphylos columbiana (Hairy Manzanita)

AD = Arctostaphylos densiflora (Vine Hill Manzanita) 
HEL = Helichrysum italicum, Helichrysum splendidum, or Helichrysum tianshanicum

MAH = Mahonia fremontii (Desert Holly) or Mahonia pinnata

PINE = Pinus aristata (Bristlecone Pine) Pinus edulis (Pinyon Pine) Pinus monophylla (Singleleaf Pinyon) or Pinus quadrifolia (Parry Pinyon) or use Quercus berberidifolia (Scrub Oak) Quercus gambelii (Gambel Oak) Quercus john-tuckeri (John Tucker Oak) Quercus vaccinifolia (Huckleberry Oak)

ROSA = Rosa glauca, or Rosa sericea var. pteracantha

SAN = Santolina chamaecyparissus (Lavender Cotton)

Perennials & Grass
ACH = Achillea tomentosa (Yarrow)

CAR = Carex comans ‘Bronze’ (New Zealand Sedge) or Carex tenuiculmis ‘Cappuccino’

ERI = Erigeron glaucus (Beach Aster)

ERY = Eryngium variifolium (Moroccan Sea Holly) Eryngium yuccifolium (Rattlesnake Master)

TUL = Tulipa dasystemon, Tulipa saxatilis, or Tulipa turkestanica (Species Tulips)

ZAU = Zauschneria californica (California Fuchsia)

Groundcover

JUN = Juniperus communis ‘Green Carpet’, or Juniperus conferta (Shore Juniper)

Mulch with crushed granite, gravel, lava rock, or other crushed rock.  Place smaller plants such as Achillea ageratifolia, Achillea clavennae, Achillea kellereri, Achillea serbica, Agave toumeyana var. bella, Cerastium tomentosum, Erigeron lineraris, Hirpicium armerioides, Lewisia tweedyi, Lewisia cotyledon, Sedum divergens, Sedum oreganum, Sedum obtusatum, Sedum oregonense, Sedum palmeri, Sedum spathulifolium, Yucca harrimaniae, Yucca nana &/or stones in open spaces as desired.  Agave & Yucca should be grown in a raised area of gravelly & rocky soil.

You can get Achillea ageratifolia, Achillea kellereri, Achillea serbica, Erigeron lineraris, Hirpicium armerioides, Mahonia fremontii, Pinus edulis, Yucca harrimaniae & Yucca nana by mail from High Country Gardens.  Pinus aristata, Quercus berberidifolia & Quercus gambelii are available from Forest Farm (other pines & oaks have been available in the past, may be in the future).

Pots on Top

 Design for a Balcony Garden

Suitable for a balcony or patio, this container garden is lightweight enough for most structures. Hardwood benches support a collection of colorful pots at least 12 inches in diameter & made of moisture-retentive glazed ceramic. They hold an assortment of herbs, flowers & vegetables in easy reach of the kitchen, where a watering can & snipping scissors are kept handy. A redwood box, planted with a Camellia & a shade-loving groundcover, is in a protected spot against the wall. The tile mosaic patio table & comfortable chairs invite the apartment dweller outside. --text from Low-Maintenance Gardening.

Plant List
A. Camellia japonica (1)
B. Allium schoenoprasum (2) Chives
C. Thymus vulgaris (1) Culinary Thyme
D. Green Onion (5)
E. Hemerocallis (1) Daylily
F. Lamium maculatum 'Beacon Silver' (4)
G. Limonium latifolium (1) Sea Lavender
H. Lobelia erinus 'Sapphire' (3)
I. Pelargonium tomentosum (1) Peppermint Geranium
J. Rosmarinus officinalis (1) Rosemary
K. Rudbeckia hirta (1) Gloriosa Daisy
L. Sedum spurium 'Dragon's Blood' (2)
M. Stachys byzantina (1) Lamb's Ears
N. Ocimum basilicum (1) Sweet Basil
O. Tomato 'Patio' (1)
P. Viola tricolor (12) Johnny-Jump-Up

I designed this garden which appeared in the 1998 Sunset publication, Low-Maintenance Gardening. It is appropriate for USDA Zone 8.