Elisabeth C. Miller Library

Gardening Answers Knowledgebase

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Recently Added Questions

Question:

What type of plant is the mistletoe people refer to during the holiday season? How did it get its name?

Answer:

There are over 1,000 mistletoe species. It is a parasitic plant that was hosted by the oak tree, but also seen on pear trees in Roman times. Mistletoe has a long history of ritual use, myth, legend, and folklore. The name 'mistletoe' comes from two Anglo-Saxon words: mistle, meaning dung, and tan meaning twig. Why "dung on a twig," you might ask. The name comes from the way the plant is propagated by birds eating the berries, then passing the seeds through the gut, and excreting the deposits onto the branches of trees. Seeds are rubbed around by the birds' beaks when they wipe them on the bark. The seeds then germinate from cracks in the twigs of the tree. The species of European lore and legend is Viscum album, which lives on deciduous tree species, such as apple and poplar. In North America, mistletoe more commonly refers to Phoradendron leucarpum. You can watch a clip of birds interacting with an Australian mistletoe species on the BBC's website. We also have in the library a copy of The Private Life of Plants by David Attenborough, which describes the phenomenon.

If you want to go deeper into the lore, we also recommend checking out The Green Mantle: An Investigation into our Lost Knowledge of Plants by Michael Jordan.

Question:

Can you tell me the name of all those shrubs with tiny purple marble-like fruit that grow along the walkway by the Intramural Activities building at University of Washington? Are they related to pepper? They look like purple peppercorns! Are they edible?

Answer:

This shrub, which goes mostly unnoticed until its dramatic fruit stands out in fall, is Callicarpa (beautyberry), most likely Callicarpa bodinieri var. giraldii 'Profusion.' Based on the size and shape of the fruit, I can see why you might think this plant could be related to pepper (the seasoning). Taxonomists have moved beautyberry around, but for now Callicarpa is in the mint family, Lamiaceae, while pepper (Piper) is in Piperaceae, and requires a warmer climate (subtropics or hotter) than ours.

Callicarpa is not listed in any of the usual sources on seriously toxic plants, but that does not mean its fruit is safe or tasty for human consumption. According to Julia Morton, a botanist and author of Wild Plants for Survival in South Florida, "the rank odor of the plant makes nibbling of beautyberry bunches on the stem unpleasant." This article from the Cape Coral Daily Breeze (February 6, 2015) mentions that birds, deer, and squirrels enjoy the fruit. In my own garden, it is not the first choice of birds, but I have seen them trying it from time to time. Humans find the fruit mealy and insipid, according to the article, but that doesn't stop avid foragers from attempting to make jelly from it.

If you grow Callicarpa, you may learn to appreciate its subtle flowers in spring, and the gently turning colors of its leaves in fall. Callicarpa americana also has terpenoids in its leaves that repel insects (mosquitoes, ticks, ants, and more).

Question:

Can you tell me more about the Shipova tree? Will it grow here in the Northwest, and is it suitable for a small garden?

Answer:

Shipova is both a common name and a cultivated variety of x Sorbopyrus auricularis. The letter x means it is a cross between Sorbus aria (whitebeam, a species of mountain ash) and Pyrus (European pear). This hybrid came about in the early 1600s in the Bollwiller (also spelled Bollwyller) castle garden in Alsace, and is propagated by grafting rather than by seeds. One of its common names is Bollwyller pear.

The fruit is shaped like a very round but small pear, and about the size of a large apricot. It ripens to a rich yellow with a blush of reddish orange where the sun reaches it. The yellow flesh is similar in flavor to pear or apple butter. There is at least one dwarf variety, 'Baby Shipova,' that is 6 to 8 feet at maturity. It can take seven years or more before it bears fruit. The variety you mention, Shipova, is self-fertile, but this tree will be more productive if planted near a late-blooming European pear for cross-pollination.

According to Ciscoe Morris, "it forms a lovely 15- to 20-foot-tall pyramidal tree with downy silver-gray pear-shaped leaves that turn pink and yellow in autumn. In April, large clusters of attractive white flowers cover the tree." It can suffer occasionally from fireblight and apple maggot. There is a chapter about Shipova in Lee Reich's Uncommon Fruits for Every Garden (Timber Press, 2004).

Question:

One of my favorite autumn things to do is shuffle through the leaves of every katsura tree I pass. What causes that enticing burnt sugar smell? Are there other trees that smell like this?

Answer:

As the leaves of katsura trees (Cercidiphyllum japonicum) begin their process of decay, they are releasing molecules of maltol into the air and conjuring up scents reminiscent of toffee, cotton candy, or—as the German common name Kuchenbaum and the French arbre à caramel suggest--baking cake and caramel.

Maltol is also found in pine needles and lark barch, but it is most famously noticeable in katsura trees as they begin to turn color and the complex sugars in their leaves break down.

Question:

It's late September and my raspberries are done producing fruit. The canes are really tall. How should I go about pruning them?

Answer:

According to Linda Gilkeson's Backyard Bounty: The Complete Guide to Year-Round Gardening in the Pacific Northwest (New Society Press, 2018), the simple method is to wait until the dormant season and cut down canes that bore fruit last year. (You can tell these canes by their rougher and darker grey bark, compared to the lighter and smoother canes of the last growing season.)

This will work for summer-bearing as well as everbearing varieties, but some choose to prune everbearing (also called primocane-fruiting) raspberries in two stages. An everbearing raspberry is one that produces fruit in the early fall of the first year on their primocanes. It then fruits a second time, in June, on buds below those which fruited the previous fall. In the dormant season, prune off only the top part of the canes that have fruited, and let the remainder fruit next summer.Then you can prune out the whole spent cane the next winter. Try to keep only five to ten new canes per plant.

This Oregon State University Extension guide to Growing Raspberries in Your Home Garden may also be helpful to you.