December 16th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (December 9 – 23, 2013)
1) Abies balsamea (Balsam fir)
- Pitch from almost every conifer is used to seal and protect wood.
- “Canada Balsam” from the Balsam Fir is used to cement together the lens elements in optical equipment and to mount specimens for microscopy.
- It is North America’s most popular Christmas tree, but only newly planted in the Arboretum in grid 42-4W.
- Native to eastern North America
2) Cedrus libani (Cedar of Lebanon)
- “Cedar oil” is distilled from several conifers, mostly not Cedrus, the “true cedar”.
- Cedar oil has insecticidal properties, was used in ancient embalming, and is currently used as immersion oil in microscopy and to mask surface flaws in emeralds.
- Several of our true cedars – Cedar of Lebanon, Atlas Cedar, and Deodar Cedar are located along the Lynn Street entrance, west of the Wilcox foot bridge.
3) Picea sitchensis (Sitka spruce)
- Before the introduction of chicle, North Americans (both natives and immigrants) chewed spruce gum.
- Spruce roots are used for stitching bark canoes and weaving hats and baskets.
- The famous “Spruce Goose” was not spruce but acquired its alliterative sobriquet because early airplane builders valued spruce’s high strength-to-weight ratio.
- Our best Sitka spruce is in 15-B on Azalea Way.
4) Pinus monticola (Western white pine)
- The Lower Kootenay Band of the Ktunaxa Nation made bark canoes from white pine bark. See the website: sturgeon-nose-creations.com
- Industrially, pine extracts make pine tar, turpentine, pitch, and rosin for violin bows, ballet shoes, baseball bats, and soldering flux.
- Pinus monticola is in the Pinetum in grid 35-6W.
5) Quercus suber (Cork oak)
- Quercus = oak, suber = cork. Location: Rock Roses on Arboretum Drive.
- Any questions?
December 1st, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (November 26, 2013 – December 9, 2013)
“Berry Best from Hollywood”
1) Ilex aquifolium ‘Ferox Argentea’ (Variegated Porcupine Holly)
- This “Punk” star is a sterile male with spiny leaves, but obviously no berries.
- But this means it doesn’t contribute to English holly’s invasiveness in the Pacific Northwest.
- Old cultivar in England, first reported in 1662 (Galle).
- Specimen is located in the Eurasian clade (family), W. berm, of the Ilex Collection.
2) Ilex maximowicziana var. kanehirae
- This “Mod” diva has a tidy upright form with black berries.
- Native to China and Japan
- Has gone through many name changes, intermediate between I. crenata and I. triflora.
- Specimen is located in the Asian/North American clade of the Ilex Collection.
3) Ilex opaca ‘Boyce Thompson Xanthocarpa’
- An American holly celebrity which dares to be different, sporting yellow berries.
- Reported to have been discovered in the wild, Mount Vernon, VA, late 1920’s.
- Specimen located in the American clade, S. berm, of the Ilex Collection.
4) Ilex verticillata ‘Winter Red’ (Winterberry cultivar)
- You don‘t always need to be dressed in leaves, says this scarlet actress.
- Reliable shrub with heavy, bright red fruit set and good berry retention.
- A nice thicket is found along Azalea Way, just north of Lookout Pond.
5) Ilex x ‘Nellie R. Stevens’
- This mischievous leading lady has been nothing but trouble!
- Claiming English holly parentage, but also Chinese holly parentage. In any case, no denying she certainly resembles English holly in my book.
- Specimen is located in the Eurasian clade, N. berm, in the Ilex Collection.
November 18th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (November 12 – 25, 2013)
1) Fokienia hodginsii (Fokienia)
- Native to China, Vietnam, and Laos
- Extremely slow growing outside of native range
- Specimen located in Rhododendron Glen
2) Keteleeria evelyniana (Keteleeria)
- Native to China, Vietnam, and Laos
- Thrives in warm climates, but may be considered an “herbaceous perennial” in northern climates
- Specimen located in north Pinetum area
3) Taiwania cryptomerioides (Coffin Tree)
- Native to Taiwan, China, and Vietnam
- Considered “critically threatened” in native range
- Specimen located near East Newton Street entrance to the Pinetum area
4) Thujopsis dolabrata (Lizard Tree)
- Native to Japan
- Thrives in moist, shady areas with rich soil
- Specimen located among Acer Collection in the Woodland Garden
5) Torreya taxifolia (Stinking Cedar)
- Native to southeastern U.S. (Florida)
- Very rare in native range due to a fungal pathogen
- Specimen located between Loderi Valley and the Woodland Garden
November 3rd, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (October 28, 2013 – November 11, 2013)
1) Arbutus unedo (Strawberry Tree)
- One of the many species described by Carl Linnaeus in his 1753 landmark work, Species Plantarum.
- An amazing plant with 4-season interest, including fruits and flowers at the same time.
- Serves as a bee plant for honey production and the fruits are food for birds.
2) Camellia wabisuki (Wabisuki Camellia)
- A Sukiya variety with single, pinkish-white flowers and an open growth habit.
- A 70-year-old specimen heralds the magnificent seasonal display in the Witt Winter Garden.
- The flowers of Wabisuki are often used in decorations for Japanese tea ceremonies.
3) Drimys winterii (Winter’s Bark or Canelo)
- A slender tree growing to 60’ feet and native to the temperate rain forests of Chile.
- For centuries, Winter’s Bark was esteemed as a preventative remedy for scurvy before vitamin C was isolated.
- Grown as an ornamental plant for its reddish-brown bark, and clusters of creamy white jasmine-scented flowers.
4) Franklinia alatamaha (Franklin Tree)
- The sole species in this genus, commonly called the Franklin Tree.
- Commercially available for garden cultivation and prized for its fragrant white flowers
- Botanist, William Bartram named this elegant tree in honor of his father’s friend, Benjamin Franklin.
5) Rhododendron occidentale (Western Azalea)
- There is considerable diversity in form and appearance of this species.
- Tolerant of serpentine soils, it is part of the unique plant community found in the Siskiyou Mountains.
- The Western Azalea was an early contributor in the development of hybrid azaleas.
October 7th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (September 30 – October 13, 2013)
The Good, The Bad and The Ugly (Minus the Good)
1) Cherry Brown Rot
- A fungal disease of the Prunus species caused by Monilina fructicola and Monilina laxa.
- The first symptoms often seen are browning and collapse of the blossoms, followed closely by death of the small twigs.
2) Dogwood Anthracnose
- Dogwood anthracnose is a disease of flowering and pacific dogwoods (Cornus florida and C. nuttallii).
- An anthracnose fungus, Discula sp., has been identified as the causal agent.
- Infection of dogwoods is favored by cool, wet spring and fall weather, but can occur throughout the growing season.
3) Elm Leaf Miner
- Elm leaf miner, Fenusa ulmi, is a pest that feeds on the tissues in between the outer layers of elm leaves, causing browning and leaf drop. Although primarily an aesthetic pest, leaf miner damage can stunt or weaken a tree when the population in the tree is high.
- The elm leaf miner has been in the Northwest for a few years, but recent expansion has been noticeable in Washington and Oregon recently.
4) Powdery Mildew on Rhododendron
- The fungus Microsphaera azalae is found throughout the Pacific Northwest on Rhododendron species and hybrids.
- Contrary to popular opinion, powdery mildew outbreaks are not favored by rainy weather. Steady rain tends to wash mildew spores off the foliage before they have a chance to penetrate the tissue. Mildew is more commonly associated with high relative humidity and the light coating of dew that forms on leaves when cool nights follow warm days.
5) Sorbus Sawfly
- The Sorbus Sawfly (Pristiphora geniculate) is a new pest in western Washington. It was first noticed in the spring of 2009 in the Everett, Lynnwood and Monroe areas.
- Sawflies that are new to an area tend to build up in large numbers and can cause significant defoliation. Sawfly larvae typically eat continuously and then drop out of sight (to pupate in the soil). Damage appears to occur overnight. Control of the first generation will reduce the number and severity of defoliation by the second and third generations.
September 23rd, 2013 by Pat Chinn-Sloan
Keystone Species of New Zealand
Keystone Species of New Zealand (September 9 – 22, 2013)
1) Nothofagus menziesii (Silver Beech, Tāwhai)
- Natural range: endemic to New Zealand. Found throughout South Island.
- Trunk is silvery-gray and has horizontal lines (lenticels).
- Dark-green, oval leaves are glossy and have toothed edges.
- Largest specimen was transplanted in Autumn 2012 with help from a very large crane.
2) Nothofagus solandri var. cliffortioides (Mountain Beech, Tawhairauriki)
- Deep green, oval leaves have a pointed tip and rolled edges.
- Grows in lowland mountain regions to about 65 feet. At high altitudes, it forms a “goblin forest” where the trees are no more than 6 feet tall.
- Two large specimens transplanted with crane in Autumn 2012.
3) Griselinia littoralis (New Zealand Broadleaf, Kapuka)
- Found throughout most of New Zealand from sea level to 3000 feet.
- Deep green, oval leaves are thick and very shiny, and this fast-growing plant is often used for hedging and shelter planting.
- Species name ‘littoralis’ means “growing by the sea”, indicating tolerance of salt spray.
4) Chionochloa rigida (Narrow-leaved Snow Tussock), C. rubra (Red Tussock)
- Genus of Chionochloa, comprises of about 20 species – all but one are native to New Zealand.
- Despite its name, C. rigida has a flowing habit reaching 3 feet with flowering stems reaching 5 feet. Leaves dry out giving the plant an overall golden color.
- C. rubra has reddish colorings with fine weeping leaves reaching 3 to 4 feet and flowering stems that rise just above the foliage.
5) Phormium colensoi (syn. P. cookianum) and P. tenax (New Zealand Flax, Wharariki)
- Both species native to New Zealand, P. colensoi is endemic; both are widespread.
- P. colensoi seed pods tilt downwards and twist in a spiral as they dry. P. tenax seeds are held upright and do not twist when drying.
- P. tenax is a larger plant with leaves reaching 9 feet and flowering stalk up to 15 feet compared to P. colensoi whose leaves reach 5 feet and flowering stalk is slightly taller at 6 feet.
September 2nd, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (August 26 – September 8, 2013)
1) Betulaceae Carpinus japonica, Corylus colurna, Ostrya carpinifolia
- Nut-bearing, often enclosed in interesting husks, cones or bracts.
2) Fabaceae Colutea orientalis
- Legumes, which are dry fruit in pods that dehisce (open along a seam).
3) Gunneraceae Gunnera manicata
- The fruit-bearing conical spike can reach 6 feet in length.
4) Magnoliaceae Magnolia grandiflora, M. officinalis var. biloba, M. sieboldii
- Cone-like fruits, from green to red, open to display bright orange seeds.
5) Myricaceae Morella californica
- The fruit is a drupe with a waxy coating that can be used to make candles.
6) Myrtaceae Callistemon sieberi
- Bottlebrush seed capsules remain unopened until stimulated by fire.
7) Paeoniaceae Paeonia rockii, P. suffruticosa
- Peony fruit pods will open when ripe to display black or bright red seeds.
8) Proteaceae Grevillea victoriae
- The profusion of colorful fruit on this shrub outshines many flowering plants nearby.
9) Rosaceae Rosa corymbulosa, R. davidii, R. roxburghii, Sorbus splendida
- Rosaceous fruit can be drupes, achenes, nuts, follicles, capsules and accessory fruits.
10) Sapindaceae Koelreuteria paniculata
- Sapindaceous fruit can be berries, nuts, drupes, schizocarps, capsules or samaras.
August 25th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (August 19 – 25, 2013)
1) Aralia elata (Japanese Angelica Tree)
- Natural range: Japan, Korea, Russian Far East
- Can be a tree more than 30 feet tall. Ours are multiple suckers from a spreading root system.
- Located north of the Wilcox footbridge (40-3W).
2) Bupleurum fruticosum
- A dense, multi-stemmed shrub tolerant of exposure and poor soil.
- Native to Southern Europe and the Mediterranean.
- Located in our Rock Rose area west of the Sorbus Collection (21-3E).
3) Kalopanax septemlobus
- A member of the Aralia family (Araliaceae), it grows to 100 feet. Its lobed leaves might be mistaken for maple until the umbels of flowers appear in July and August.
- Native to Japan, Korea, and the Russian Far East.
- Our best is located west of Azalea Way in 15-1W.
4) Poliothyrsis sinensis
- Native to the Chinese province of Hupeh
- Bears clusters of fragrant white flowers
- Located south of the Woodland Garden near other so-called primitive trees: Trochodendron, Tetracentron, and Euptelia.
5) Rosa sp. with Spiny Rose Gall
- These galls are caused by a tiny wasp, probably Dipolepis bicolor, which lays its eggs in the rose’s leaves. The larvae live in the galls until the following spring.
- This plant is located in 25-1E at the intersection of the Upper and Lower Trails.
August 2nd, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (7/29/13 – 8/12/13)
“Can You Smell That Smell?”
1) Clerodendrum trichotomum
- Repugnant, peanut-butter odor when leaves are bruised!
- Cats are attracted to the smell.
- See our suckering forest of young trees along the path leading down to the WPA horticultural crew barn.
2) Prostanthera cuneata (Alpine Mint-Bush)
- This low-growing shrub is from Australia and is in the Mint family.
- When leaves are crushed, they emit a strong fragrance that some liken to eucalyptol and smelly socks.
- Located in the Australian exhibit of the Pacific Connections Garden.
3) Ribes malvaceum var. viridifolium ‘Ortega Beauty’ (Chapparal Current)
- Native to the coastal mountains of southern California.
- Malodorous skunky scent when leaves are rubbed like many plants in a chapparal community.
- Located in the Cascadian entry exhibit of the Pacific Connections Garden.
4) Umbellularia californica (Headache Tree)
- Large broadleaf evergreen tree.
- Most odoriferous tree in our plant collections by far.
- Take a deep whiff of the crushed leaves and you’ll know right away why it’s called the headache tree!
5) Vitex agnus-castus (Monk’s Pepper)
- Peppery-smelling leaves some folks compare to Cannabis.
- An ornamental summer-flowering shrub with many medicinal qualities.
- Located along Azalea Way at the SE entrance to the Woodland Garden.
July 18th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (July 15-31, 2013)
1) Quercus x bushii ‘Seattle Trident’
(Seattle Trident Hybrid Red Oak)
- Cultivar of a Black Oak and Blackjack Oak hybrid.
- Developed in Sir Hillier Gardens and Arboretum in England from scion wood collected at Washington Park Arboretum.
- Located in the Oak Collection, northwest of Azalea Way service road intersection.
2) Quercus dentata (Daimyo Oak)
- Asian native (China, Korea, Japan, Mongolia)
- Develops an unusually large leaf; occasionally used as a vegetable in native range.
- Located in the Oak Collection on hillside near Foster Island Road.
3) Quercus macrocarpa (Bur Oak)
- Native to Eastern and Midwestern U.S.
- Develops a distinct broad canopy as tree matures.
- Located in the Oak Collection along ridge west of Azalea Way.
4) Quercus muhlenbergii (Chinquapin Oak)
- Broad, native range spanning from New England to northeast Mexico.
- Large, slow growing tree with chestnut-like foliage.
- Located in the Oak Collection along ridge west of Azalea Way, north of the Bur Oak.
5) Quercus pontica (Armenian Oak)
- Native to the Caucasus Mountain region of Eastern Europe.
- Shrubby oak: leaves on new wood remain evergreen, yet older wood becomes deciduous.
- Located in the Oak Collection near entrance to the Graham Visitor’s Center.