Sunday, April 26, 2009

How to Design a Thicket


Thickets are mysterious: dense, dark & impenetrable. They harbor wildlife, heard yet unseen. They are low-maintenance, best left unpruned & unwatered. Thickets may take the place of a bosque where height is restricted.

1 Define a space in your garden. Thickets are easy to maintain, so this can be a fairly large space. A thicket should cover a space at least 10 feet in each dimension. Thickets can be used as screens 10 feet wide.

2 Choose small deciduous trees, shrubs & ferns. A thicket should consist of plants that tolerate both sun & shade. The center of a thicket becomes densely shaded, while the south & west edges can be very sunny. Choose both evergreen & deciduous shrubs.

3 Buy lots of compost. You can order it by the truckload from Cedar Grove, or buy it in bags. Cover the garden site 2 feet deep. Plant in the compost.

4 Buy the plants. No single nursery will have all of the plants you want & need. Call around. Look in the phone book under Nurseries.

5 Space the plants at appropriate distances. Find out how big these plants will get. Plant them closely enough that the branches will interlock, but not so closely that they are crowded. 3 to 5 feet apart is good for most shrubs, 7 to 10 feet apart for trees.

6 Plant shady, drought-tolerant groundcovers under shrubs.

7 Cover open ground with mulch. Buy shredded bark. Use mulch from your compost pile or worm bin. Keep mulch under 2 inches deep.

8 For the 1st few years, water regularly during summer. Pull out weeds. Replace dead plants. Prune lightly around the edges, or not at all. Continue to watch for invasive plants like Blackberry, Holly & Ivy.

Plants for Thickets
Small Trees: deciduous, except as noted
Acer circinatum (Vine Maple)
Hamamelis x intermedia (Witch Hazel)
Pinus contorta var. contorta (Shore Pine): evergreen
Prunus ilicifolia (Hollyleaf Cherry): evergreen
Sorbus forrestii (Mountain Ash)

Shrubs: for sun or shade
Arbutus unedo ‘Compacta’ (Compact Strawberry Tree)
Holodiscus discolor (Oceanspray)
Mahonia aquifolium (Oregon Grape)
Oemleria cerasifera (Indian Plum)
Pieris japonica (Lily of the Valley Shrub)
Ribes sanguineum (Flowering Currant)
Styrax redivivus (Snowbell)
Vaccinium ovatum (Evergreen Huckleberry)

Ferns & Groundcovers: for shade
Dicentra formosa (Bleeding Heart)
Fragaria vesca (Woodland Strawberry)
Maianthemum dilatatum (False Lily of the Valley)
Oxalis oregana (Redwood Sorrel)
Polystichum munitum (Swordfern)

Design for a Thicket

Trees
Shrubs
Fern

Saturday, March 28, 2009

How to Design a Mixed Border

Mixed borders (or mixed planting beds) are those that combine shrubs & perennials. They have outpaced perennial beds to become the most common type of planting in Seattle. There is good reason for this. Mixed borders are more visually appealing, more varied, more interesting & less work than perennial gardens. Cottage gardens usually refer to perennial beds, but the cottage garden style is frequently applied to mixed plantings. Perennials & shrubs are most often informally intermixed.

1 Find a sunny site. This technique can work in shade. But it is easier in sun.

2 Choose a theme. You might choose plants from a certain region.  But it is probably easiest to work with color. You might decide to use a variety of different colors, a dominant single color, or a pair of contrasting colors. Don’t make it too complex. Try to take it easy.

3 Choose your favorite shrubs from lists of plants that match your theme. Shrubs will take up the most space. Decide where to place them 1st. Realize that they will cast shade as they grow. Learn their ultimate size in order to leave enough space between them for perennials. Consider repeating certain shrubs. Keep it simple.

4 Choose your favorite perennials from lists of plants that match your theme. Here you will be thinking more of flowers. But foliage is still important. Don’t use too many spiky-leaved perennials. This is easy to do. It looks boring. Think of grasses, bulbs & groundcovers as perennials. Be sure to repeat certain perennials. 1 of everything is just a big chaotic mess.

5 Buy lots of compost. You can order it by the truckload from Cedar Grove, or buy it in bags. Cover the garden site 2 feet deep. Plant in the compost.

6 Buy the plants. No single nursery will have all of the plants you want & need. Call around. Look in the phone book under Nurseries. Visit ALL of the nurseries near you. Order plants by mail, if they are unavailable locally.

7 Set the plants out on the compost. Shrubs should be near the center of the bed to give them room to spread. (This is particularly important if you are planting along a wall.) Place shorter perennials in front of shrubs & underneath them. Place taller perennials between shrubs. Place the tallest perennials at the back between shrubs, if you are planting along a wall. If you intend to walk around the planting bed, place the tallest perennials in the center between shrubs.

8 Move the plants while still in their pots. Shift them to allow the appropriate space between them. Be sure you know how big these plants will get. Buy a book which describes the growth habit & ultimate size of a variety of plants. The Sunset Western Garden Book is excellent for this purpose.

Design for a Mixed Border

AST = Aster
NAR = Narcissus

Saturday, March 21, 2009

How to Design a Privacy Screen

A privacy screen is used when you don't want to see what is beyond your property line, which might be the street, or the sidewalk, or in the case of 1 of my clients: a gas station.  It gives a sense of enclosure to your garden.  It creates a pleasing backdrop to your other plantings.  It can become part of a mixed border.  It is probably better to use a fence, if your space is tight.  But a privacy screen can grow much taller than a fence is permitted.  It is often less expensive.  Of course, it takes time to grow.  I don't recommend clipped hedges, which are high-maintenance & have a rigid, sometimes tortured appearance. Privacy screens can be pruned to limit spread & height, yet maintain a natural appearance. 

1 Choose the site. It will most likely lie along your property line. Allow plenty of room: a strip from 5 to 10 feet wide.

2 Choose 3 to 7 shrubs, depending on the length of the strip. Is the site mostly shady or sunny? If it has shade in part & sun in part, choose 3 to 5 shrubs for each part. Do not plant only 1 kind of shrub. That is called a hedge. Hedges are boring.

3 Buy lots of compost. You can order it by the truckload from Cedar Grove, or buy it in bags, Cover the garden site 2 feet deep. Plant in the compost.

4 Buy the plants. No single nursery will have all of the plants you want & need. Call around. Look in the phone book under Nurseries.

5 Space the plants at appropriate distances. Find out how big these plants will get. Give them enough room. If you don’t, you will have to remove them later.

6 Plant shady groundcovers under shrubs.

7 Cover open ground with mulch. Buy shredded bark. Put mulch from your compost pile or worm bin over open spaces in the garden. Always mulch around new plantings. Keep mulch under 2 inches deep.

8 Patrol the strip regularly: become territorial. Pull up weeds. Water regularly during summer. Replace dead shrubs. As the shrubs grow, notice the privacy they provide.

9 Buy pruning tools. You need pruners, loppers & a folding pruning saw. Go to a big hardware store. Cut off dead & broken branches. Do not shear the shrubs like a hedge. Learn about pruning. Buy a book which illustrates pruning & other gardening techniques. The Sunset Western Garden Book is good to start.

10 (Optional) If you have prepared a 10 foot strip, plant evergreen & deciduous shrubs in front of the spaces between evergreens. This will increase privacy & create more interest in fall & winter. Consider shrubs with fruits & berries, as well as shrubs with colorful fall foliage. A mixed border can also be used.

Evergreen Shrubs for Privacy Screens
Abelia x grandiflora: sun or part shade
Arbutus unedo ‘Compacta’ (Campact Strawberry Tree): sun or shade
Berberis darwinii (Darwin's Barberry): sun
Callistemon rigidus (Bottlebrush): sun
Calycanthus floridus (Carolina Allspice) Calycanthus occidentalis (Spice Bush): shade
Ceanothus ‘Victoria’ (California Lilac): sun, fast growth, but short-lived
Choisya ternata (Mexican Orange): sun  or part shade
Elaeagnus x ebbingei, Elaeagnus pungens (Silverberry): sun 
Erica arborea, Erica australis (Tree Heath): sun
Gaultheria shallon: sun or shade
Hypericum ‘Hidcote’ (St John’s Wort): sun
Ilex crenata (Japanese Holly): sun or shade
Itea ilicifolia: sun or shade
Juniperus chinensis ‘Blue Point’ (Chinese Juniper) Juniperus communis 'Hibernica' (Irish Juniper): sun
Ligustrum japonicum (Japanese Privet): sun or shade
Nandina domestica (Heavenly Bamboo): shade
Mahonia aquifolium (Oregon Grape): sun or shade Mahonia bealei (Japanese Mahonia): shade
Myrica californica (California Wax Myrtle): sun or shade
Pieris japonica (Lily of the Valley Shrub): shade
Rhododendron: shade
Taxus baccata 'Fastigiata' (Irish Yew): sun of part shade
Thuja occidentalis (Arborvitae): sun or part shade
Vaccinium ovatum (Evergreen Huckleberry): sun or shade
Viburnum tinus: sun or shade

 Design for a Privacy Screen

A = Arbutus unedo ‘Compacta’ (Compact Strawberry Tree)
C = Callistemon rigidus (Bottlebrush)
E = Erica arborea (Tree Heath)
S = Syringa meyeri 'Palibin' (Korean Lilac)

Saturday, March 14, 2009

How to Design a Bosque

A bosque is a grove of trees. Some mimic the forest, while others are more formal. Trees are spaced regularly, or more randomly. Bosques are evergreen, deciduous, or both. Larger bosques often have more kinds of trees. Trees planted in a grid may be underplanted randomly with shrubs & perennials. This technique was used to good effect at the Olympic Sculpture Park in Seattle, also at Schloss Nymphenburg in Munich. Large bosques grace many European palace gardens. Smaller bosques are lovely in all (except the smallest) gardens.

1 Choose the site. It will most likely lie in a corner of your property line. Allow plenty of room. The area should be at least 15 feet wide on 2 sides.

2 Choose at least 5 trees: all the same, or 2 different kinds. Also choose any number of shrubs, perennials & groundcovers for the shaded ground beneath the trees.

3 Buy lots of compost. You can order it by the truckload from Cedar Grove, or buy it in bags, Cover the garden site 2 feet deep. Plant in the compost.

4 Buy the plants. No single nursery will have all of the plants you want & need. Call around. Look in the phone book under Nurseries.

5 Space the plants at appropriate distances. Find out how big these plants will get. Give them enough room. If you don’t, you will have to remove them later. Plant trees 5 to 10 feet apart, depending on their ultimate size.

7 Cover open ground with mulch. Buy shredded bark, put mulch from your compost pile or worm bin over open spaces in the garden. Always mulch around new plantings. Keep mulch under 2 inches deep.

8 Patrol the strip regularly: become territorial. Pull up weeds. Water regularly during summer. Replace dead plants. As the trees grow, enjoy the shade they provide.

9 Buy pruning tools. You need pruners, loppers & a folding pruning saw. Go to a big hardware store. Cut off dead & broken branches. Learn about pruning. Buy a book which illustrates pruning & other gardening techniques. The Sunset Western Garden Book is good to start.

Trees for Bosques
Acer circinatum (Vine Maple)
Acer griseum (Paperbark Maple)
Aesculus californica (California Buckeye)
Araucaria araucana (Monkeypuzzle)
Nothofagus antarctica (Southern Beech)
Pinus densiflora (Japanese Red Pine)
Quercus suber (Cork Oak)
Sequoia sempervirens (Coast Redwood)
Sorbus alnifolia (Mountain Ash)
Thuja plicata (Western Red Cedar)


 Design for a Small Bosque

A = Acer circinatum (Vine Maple)
C = Chamaecyparis obtusa ‘Gracilis’ (Slender Hinoki Cypress)

Sunday, February 22, 2009

West Coast Perennial Garden (Cascadia Garden)

Iris tenax May 2009

Iris macrosiphon May 2009
 
 Erythronium oregonum March 2010

Lithocarpus densiflorus echinoides May 2009

This small garden features perennials from Washington, Oregon & California. It started with 8 Pacific Coast Native Iris: 3 succeeded. At the center of the garden Arctostaphylos ‘Monica’ grows in a large earthen pot. Allium & Iris encircle it. Lilies grow in the open area beyond. Lithocarpus densiflorus echinoides waits in back, growing slowly.  After 5 years, it is 2 feet tall. Heuchera micrantha & Tellima grandiflora linger under a tall, spreading Mahonia aquifolium. Fragaria vesca spread quickly throughout. The garden was started in 2004, replacing the lower half of the Rock Garden. Spanish Narcissus bulbocodium remained in place.  Japanese Ajuga reptans has crept into the garden now.  I don't want to kick it out. There is also the Australian Pratia pedunculata that I cannot stop.

West Coast Perennial Garden Plant List
Shrubs
Mahonia aquifolium (Oregon Grape)

Perennials
Allium cernuum (Nodding Onion)
Erigeron glaucus (Beach Aster)
Erythronium oregonum (Fawn Lily)
Iris douglasiana (Douglas Iris)
Iris macrosiphon (Ground Iris)
Iris tenax (Oregon Iris)
Lilium columbianum (Tiger Lily)
Lilium pardalinum (Leopard Lily)
Sisyrinchium californicum (Yellow-eyed Grass)
Tellima grandiflora (Fringecup)

Groundcover
Fragaria vesca (Woodland Strawberry)

Sunday, February 15, 2009

Privacy Screen (Cascadia Garden)

Hebe ochracea in front of Chamaecyparis lawsoniana ‘Blue Surprise’ May 2009

Aster in front of Juniperus chinensis ‘Blue Point November 2008


The double row of shrubs evolved along the north edge of the Cascadia Garden between 2003 & 2008. A tall Rosa ‘Queen Elizabeth’ remains from the rose garden period prior to 1992. Roses are not effective screens, but this gives a glimpse of neighboring lawn. In 2003 Thuja occidentalis ‘Yellow Ribbon’ & Juniperus chinensis ‘Blue Point’ were planted, the remaining shrubs were added in 2007. Screening was more effective with more evergreen shrubs.  Smaller shrubs & perennials are planted south of the screen, where they bask in full sun.

Privacy Screen Plant List
Shrubs: evergreen except as noted
Callicarpa bodinieri (Beautyberry): deciduous
Callistemon sieberi (Bottlebrush)
Rosa ‘Queen Elizabeth’ (Grandiflora Rose): deciduous

Groundcovers
Fragaria vesca (Woodland Strawberry)
Geranium himalayense (Cranesbill)

Friday, January 23, 2009

Bosque (Cascadia Garden)

 Chamaecyparis lawsoniana December 2008

Sorbus gonggashanica September 2008


Mahonia aquifolium January 2010

Helleborus x hybridus January 2010

The bosque evolved over more than 40 years. Trees, shrubs & perennials were slowly added. The bosque is now composed of 5 large evergreen trees; 4 Chamaecyparis lawsoniana & 1 Thuja plicata. Acer circinatum & Sorbus gonggashanica grow at the edges. 4 hybrid Rhododendron cast additional shade. The bosque is located at the southwest corner of the property where land slopes to the west. It had been a very dry site. Plants for dry shade have been most successful there. The ground is covered mostly by Washington native forest plants & Helleborus x hybridus.

Bosque Plant List
Trees
Acer circinatum (Vine Maple)
Chamaecyparis lawsoniana (Port Orford Cedar)
Sorbus gonggashanica (Mountain Ash)
Thuja plicata (Western Red Cedar)

Shrubs
Holodiscus discolor (Ocean spray)
Mahonia aquifolium (Oregon grape)
Philadelphus lewisii (Mock Orange)
Ribes sanguineum ‘Pokey’s Pink’ (Flowering Currant)

Perennials & Groundcovers
Achlys triphylla (Vanilla Leaf)
Campanula poscharskyana (Serbian Bellflower)
Dicentra formosa (Bleeding Heart)
Liriope spicata (Lily Turf)
Maianthemum dilatatum (False Lily of the Valley)
Oxalis oregana (Redwood Sorrel)
Polystichum munitum (Sword Fern)
Smilacina racemosa (False Solomon’s Seal)

Sunday, January 18, 2009

Mixed Border (Cascadia Garden)

 Agapanthus africanus August 2008



Kniphofia thompsonii thompsonii June 2009

Eryngium amethystinum August 2008

The mixed border is 5 feet wide x 38 feet long. It began in 1993 with plants that had blue (gray) foliage, or blue or yellow flowers. Eventually I felt that lacked depth. Purple & orange flowers added richness. The mixed border runs along house for half its length, then past the deck, across a path, & along the south edge of the vegetable garden. It borders a brick walk (also 5 feet wide) leading to the front porch & door. The paving pattern is a series of squares within squares. The bricks are set in a bed of sand flanked by railroad ties. A mixed border is a long, narrow bed planted with both shrubs & perennials.

Early in January Euphorbia rigida blooms yellow against blue foliage. The effect is repeated by Euphorbia myrsinites & Narcissus some weeks later.  In June Hypericum 'Hidcote' shows bright yellow flowers against the thick & fluffy blue blossoms of Ceanothus, with dark purple Geranium phaeum behind. In summer blue Agapanthus, orange Crocosmia, yellow Hemerocallis & yellow + orange = bicolor Kniphofia bloom together. All are tempered & enriched by the ever-blue foliage of Eucalyptus moorei, Hebe, Juniperus chinensis ‘Blue Point’. A blot of red Lobelia tupa gives a modern art effect in late summer. In the small section fronting the vegetable garden, decorative vegetables grow (Chinese Lanterns, Leeks, Rhubard, Sea Kale) along with Narcissus & Tulipa.

Blue & Yellow Mixed Border Plant List
Trees

Shrubs
Ceanothus ‘Victoria’ (California Lilac)
Hypericum ‘Hidcote’ (St John’s Wort)
Juniperus squamata ‘Loden’

Perennials
Agapanthus ‘Storm Cloud’ (Lily of the Nile)
Crambe maritima (Sea Kale)
Digitalis trojana (Trojan Foxglove)
Geranium phaeum (Mourning Widow)
Lobelia tupa (Tupa)
Narcissus (Daffodil)
Rheum x cultorum (Rhubarb)

Groundcovers
Euphorbia myrsinites (Myrtle Spurge)
Pratia pedunculata (Blue Star Creeper)

Wednesday, December 24, 2008

Cupressaceae: The Cypress Family

Cupressus sempervirens illustration by Maxfield Parrish 1903


Juniperus chinensis December 2009

Cupressaceae (the Cypress family) is exceptionally useful in Pacific Northwest gardens. Many members of the family grow here as native plants. The Cypress family includes species of Chamaecyparis & Thuja such as Alaskan Cedar, Port Orford Cedar, & Western Red Cedar. Chamaecyparis nootkatensis ‘Pendula’ has a very graceful, open form. Chamaecyparis lawsoniana has many attractive dwarf forms such as ‘Blue Surprise,’ ‘Lutea Nana’ & ‘Somerset.’ A smaller, narrower form of Thuja plicata (Western Red Cedar) is ‘Fastigiata.’ Other widely used genera of the family Cupressaceae are Cupressus, Juniperus, Thujopsis & exotic members of the genus Chamaecyparis such as Hinoki Cypress & Sawara Cypress. There are so many Junipers, I wouldn’t know where to begin. Don’t make the mistake of hating all Junipers because of the ubiquitous, sprawling Juniperus chinensis ‘Pfitzeriana.’ The Hillier Gardener’s Guide to Trees & Shrubs says Cupressus sempervirens ‘Swane’s Golden’ is 1 of the best medium-sized golden conifers for the small garden. Various forms of Chamaecyparis obtusa are popular here for their exceptional beauty. Chamaecyparis pisifera ‘Boulevard’ is a nice small tree with fluffy, blue foliage.

Familiar Members of Cupressaceae
Chamaecyparis (False Cypress)
Cupressus (Cypress)
Juniperus (Juniper)
Metasequoia (Dawn Redwood)
Sequoia (Coast Redwood)
Sequoiadendron (Sierra Redwood)
Thuja (Arborvitae)
Thujopsis (False Arborvitae)

Cupressaceae for Pacific Northwest Gardens
Chamaecyparis obtusa ‘Gracilis’ (Slender Hinoki Cypress)
Cupressus sempervirens (Italian Cypress)
Juniperus communis ‘Compressa’ (Dwarf Irish Juniper)
Juniperus conferta (Shore Juniper)
Thuja koraiensis (Korean Arborvitae)
Thujopsis dolabrata ‘Nana’ (Dwarf False Arborvitae)

Saturday, December 13, 2008

Ericaceae: The Heath Family

Erica australis February 2009

 
Erica manipuliflora September 2009




Ericaceae is an important family of plants for Seattle gardens. Northwest natives, as well as favorites from Europe & Asia are among the ericaceous shrubs. The family was named for the genus Erica (Heath). Most members of the family have clusters of urn-shaped flowers, although some like Rhododendron have bell-shaped flowers, as though the urn had split into lobes. As a family many share a distinctive rounded form & branching pattern. They are mostly evergreen with leathery leaves. There is a great wealth of different & pleasing shrubs among Rhododendron species. The same is true of Arctostaphylos (Manzanita). These 2 thrive in very different environments. The center of Rhododendron diversity is in the moist & forested Himalayas. Manzanitas are centered in the dry chaparral of southwestern North America. Useful Northwest native plants in this family include Arctostaphylos columbiana (Hairy Manzanita), Arctostaphylos uva-ursi (Kinnikinnick), Arbutus menziesii (Madrona) & Gaultheria shallon (Salal).

Trees
Arbutus unedo (Strawberry Tree)

Shrubs
Arctostaphylos columbiana (Hairy Manzanita)
Calluna vulgaris (Heather)
Daboecia cantabrica (Irish Heath)
Erica arborea (Tree Heath)
Kalmia latifolia (Mountain Laurel)
Menziesia ferruginea (Fool’s Huckleberry)
Pieris japonica (Lily of the Valley Shrub)

Groundcovers
Arctostaphylos uva-ursi (Kinnikinnick)
Gaultheria procumbens (Wintergreen)