October 18th, 2014 by Catherine Nelson, Adult Tours Program Assistant
The Liquidambar styraciflua, or Sweetgum, is one of autumn’s most brilliantly colored trees, its leaves showing off every color in the spectrum.
The Liquidambar was wide spread, existing all over the Northern Hemisphere during the Tertiary Period (250-65 million years ago), but mostly disappeared due to glaciation during the ice age. Now this tree is native only to the SE United States and some areas of Mexico and Central America. These deciduous trees can grown to 80-100 feet tall & live up to 400 years. Its species name in Latin means ‘flowing with resin’ as the sweet resin in this tree was originally used for chewing gum.
They can be mistaken for maples as they have a similar palmate leaf. The Sweetgum leaf has 5-7 pointed lobes, but is usually flat along the bottom. They also have a distinctive spiky brown fruit in autumn.
Our free Weekend Walks 10/19 – 11/16 will take visitors to view this and other deciduous plants in our collection. Please join us. See Visit > Tours for more information.
July 27th, 2014 by Catherine Nelson, Adult Tours Program Assistant
This photo is of a native Thuja Plicata (common name; Western Red Cedar) and shows the great J-arm branches that these trees feature. Although the Puget Mill Company logged most trees on the site by 1900, this particular Thuja was perhaps overlooked by the loggers and is therefore one of the oldest and largest specimens in the arboretum. It is located between the Witt Winter Garden and Azalea Way.
This tree species was valued by the local Salish tribes who called it the “tree of life” as it provided them with bark for clothing, dried leaves for a medicinal tea, and planks for longhouses among many other uses.
Our August Free Weekend Walk’s topic is Native Plants & People; a knowledgeable guide will talk about this tree and various other native plants and their ethnobotanical uses.
May 4th, 2014 by Catherine Nelson, Adult Tours Program Assistant
Paulownia tomentosa, Common name Empress Tree
Right now this tree’s large purple panicled flowers, which look similar to foxglove flowers, are blooming and the scent is wonderful. There are several in the UWBG collection, most located at the North end of the park where the wetlands trail begins.
It is a very fast growing tree that can reach 80 ft. in height, and is prized for its large heart-shaped fuzzy leaves. The large size of young growth can be enhanced if the tree is pollarded yearly; the pruning encourages growth of leaves up to 16” across.
It is classified as an invasive plant in the Southern United States, where it sends out invasive roots and can take over the area it is planted in. The Paulownia here in the Pacific Northwest do not behave invasively, probably due to our cooler climate.
The name Paulownia is in honor of the Grand Duchess Anna Pavlovna of Russia, with tomentosa being derived from the Latin meaning ‘covered in hairs’.
Paulownia is cultivated as an ornamental tree in parks and gardens. It has earned the Royal Horticultural Society’s Award of Garden Merit.
In its native China, an old custom is to plant an Empress Tree when a baby girl is born. The fast-growing tree matures when she does. When she is eligible for marriage the tree is cut down and carved into wooden articles for her dowry. Carving the wood of Paulownia is an art form in Japan and China. In legend, it is said that the phoenix will only land on the Empress Tree and only when a good ruler is in power. Several Asian string instruments are made from P. tomentosa, including the Japanese koto and Korean gayageum zithers.
April 19th, 2014 by Catherine Nelson, Adult Tours Program Assistant
Rhododendron macabeanum is one of the finest big leaved Rhododendron species and has received the Royal Horticultural Society’s Award Of Garden Merit. It has large yellow/white flowers often blotched purple inside with an interesting bright pink stigma. The leaves are a dark glossy green and about 1′ in length with a light colored indumentum on the underside. It also bears a nice silvery young leaf and bright red bud scales.
Native to India at high elevations, this plant was introduced to the West in 1927. We have a wonderful specimen in the arboretum. It is blooming right now and is located between the SE corner of Loderi Vally and the Magnolia Collection. Our April Free Weekend Walks on Sundays at 1:00 pm will continue to feature this and other amazing Rhododendrons in the UWBG collection.
April 5th, 2014 by Catherine Nelson, Adult Tours Program Assistant
The Rhododendron occidentale is one of two NW native Rhododendron species (the other being our Washington State Flower, Rhododendron macrophyllum).
Commonly called Western Azalea or Honeysuckle Shrub, it is found along the Pacific Coast from lower Washington to central California. This species shrub is tolerant of wet soils and can be found in wetlands and along creeks in its native environment.
These Azaleas can grow to 15 ft. in height and do well in our Seattle climate when provided some shade, though they are not drought tolerant in summers. They are prized for their beautifully colored pink/white/yellow flowers, which are extremely fragrant this time of year.
John Muir encountered the shrub in the Yosemite region & said of it, “It is very showy & fragrant, & everybody must like it not only for itself but for the shady alders & willows, ferny meadows, & living water associated with it.”
Our UW Botanic Gardens’ Free Weekends Walks for the month of April will feature Rhododendron species and cultivars during their their peak bloom time. Please join us any Sunday at 1:00pm at the Graham Visitors Center to learn more.
February 2nd, 2014 by Catherine Nelson, Adult Tours Program Assistant
The winter blooming shrubs Hamamelis, or Witch Hazels, are currently at peak bloom sending out their lovely aroma and luring visitors into The Witt Winter Garden. This plant and other winter bloomers will be featured during the month of February on our Sunday Free Weekend Walks.
This large shrub or small tree is native to North America, Europe and Asia and features the species Hamamelis virginiana, H. ovalis, H. venalis, H. japonica & H. mollis.
The origin of the plant’s common name comes from the Old English word ‘Wych’, meaning ‘bendable,’ and has evolved into the modern spelling of ‘Witch.’ The limbs of this plant were traditionally used for Dowsing which is how it came to be know as Water Witching.
Hamamelis is Latin for “together with fruit” which refers to the simultaneous occurrence of flowers with maturing fruit from previous year. These fruits can split explosively at maturity, ejecting seeds up to 10 meters.
Native Americans used Witch Hazel bark to treat sores, tumors, bruising and skin ulcers. Boiled twigs were used to treat sore muscles and a tea was used to treat coughs, colds and dysentery
The nutty seeds from the Witch Hazel were also a Native-American favorite because of their flavoring, which is similar to pistachios.
January 26th, 2014 by Catherine Nelson, Adult Tours Program Assistant
Our free public tours of the Washington Park Arboretum have begun for the new year. We hold these tours as Free Weekend Walks every Sunday from January through November. The walks are led by an experienced docent and last about 90 minutes. With over 10,500 plants in the arboretum collection we don’t run out of topics to share with our visitors.
For the month of January we had 90+ visitors come along and learn about Ancient Tree Species that have been living on earth for millennia. If you missed this month, there are more season topics to explore through the rest of the year.
One of our most popular tours is coming up in February; The Joseph Witt Winter Garden. Everyone wants to see and smell flowers this time of year to remind us that spring is around the corner. Following February, our Spring tours will take visitors to see all the amazing flowering plants in the collection.
Tours meet at the Graham Visitors Center, Sundays at 1:00pm and we go out rain or shine. You can find the monthly topics by visiting our web site and clicking on Visit then Tours. Hope you can join us soon – tell your friends!
January 4th, 2014 by Catherine Nelson, Adult Tours Program Assistant
Euonymus europaeus ‘atrorubens’
Tucked away behind the Cedrus knoll in the Arboretum’s Pinetum is the Euonymus europaeus ‘atrorubens’. At this time of year it is showing off its colorful seed pods, which hang all over the defoliated branches. A plant that has pink and orange fruits really catches your eye when you pass by.
This shrub is native to Europe and Western Asia and its common names are Spindle Tree and Cat Tree. It grows to 8′-10′ making it a good plant for a sunny spot in an urban garden. The flowers are borne in the spring and are insignificant, but the plant is used ornamentally for its red fall color and brilliant winter seed pods.
July 31st, 2013 by Catherine Nelson, Adult Tours Program Assistant
In the midst of our dry NW summer, while many plants look worse for wear, our native evergreen Salal shrubs, Gaultheria shallon, are shiny and healthy. Salal flowers in the spring with pinkish-white bell-shaped flowers in groups of 5-15 on racemes; very similar to the Pieris japonica flower. Both plants are in the Ericacea family. The Salal shrub can grown to 16′ tall and forms a dense mass that creates habitat and food for local birds and animals. It is a coniferous forest understory plant that is widespread in lower, coastal elevations.
Salal is used world-wide in floral arrangements for its long lasting fresh evergreen foliage and is harvested locally in a multimillion dollar industry. However, the harvesting of the foliage in the wild is protected by the US Forest Service by issuance of permits – this is to save our native plant from over harvesting and ensure its continuance in the wild.
The name Salal is derived from the Chinook language. The small sweet blue colored berries, which are ripe right now, were harvested and eaten by the local Salish peoples; consumed as a fresh fruit in summer, used to sweeten fish roes and soups, and mixed with fish oil and dried in cakes for winter consumption (an early version of fruit leather).
Salal is one of the NW native plants that will be featured in August’s Free Weekend Walks at the Washington Park Arboretum.