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Elisabeth C. Miller Library

Archives: Plant Answer Line Q & A

Plant Answer Line questions and answers.

Neomarica culture

I saw this plant while visiting a friend in Florida. What is it? Can I grow it in Seattle?

 

 

This is Neomarica gracilis, a plant in the iris family that is also called walking iris or apostle plant. The common name ‘walking iris’ derives from the way the plant propagates itself: as stems mature, they bend to the ground and take root (when humans propagate plants by doing this intentionally, it is called ‘layering’). The name ‘apostle plant’ refers to anecdotal observations that Neomarica will not flower until it has produced at least twelve leaves.

It is not likely to thrive in the Pacific Northwest; its native range is from Mexico and Costa Rica south to Brazil. Pacific Bulb Society lists it and other species, for adventurous gardeners who are eager to grow plants that stretch beyond our hardiness zone. Local botanist and gardener Sami Gray has this to report: “It’s a tender semitropical, so here it’s a house plant. It did well enough for me for years, then I despaired of getting it to bloom when I was looking: the flowers are very short-lived.” Daniel Sparler mentions growing a different species, Neomarica caerulea, in this Northwest Horticultural Society article: “When the mood strikes it, from tall, elegant lance-shaped foliage emerges a blossom stalk with a dozen or so coy buds that suddenly burst forth one fine morning with the most captivating purple-blue flags and falls that open to reveal intricate, internal ivory and chocolate striations. Although individual flowers last only a few hours before swooning, up to six may open at once on the same stalk.”

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Fire resistant garden design

Are there resources for designing fire-resistant gardens in the Pacific Northwest?

 

The Miller Library has the book Fire-Resistant Plants for Home Landscapes (also available online) which should be a good starting point.

The King County Forestry Program also has a list of Fire-resistant Landscape Plants for the Puget Sound Basin.

For those who garden further east in Washington, there is a list from Chelan/Douglas County Master Gardeners.

Still further afield, there are many resources from California:

There are increasing numbers of gardening books that address climate change and related challenges. Here are two examples:

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Hawaiian sandalwood

I was browsing a 1965 book on the plants of Hawai’i and found an old magazine clipping inside about the vanishing of sandalwood from the islands. It described native Hawaiians cutting sandalwood trees to fill pits in the earth dug deep as the hold of a ship. Is it true that sandalwood has disappeared from Hawai’i?

 

When the first people arrived in Hawai’i by canoe, Sandalwood (Santalum freycinetianum and other species, or ‘iliahi, the Hawaiian name for the tree) grew abundantly. They found medicinal and other practical uses for the tree, including using the pulverized wood to scent bark cloth used for clothing and bedding.

With the late 18th century arrival of explorers like American sea captain John Kendrick and Captain James Cook of England came the exploitation of the islands’ natural resources. The intensification of trade in sandalwood altered the Hawaiian way of life. Recognizing that there was value in this trade, King Kamehameha I was unwittingly complicit in altering “the production-for-use economy into a production-for-profit economy.” He sent his subordinates to order common people to collect sandalwood in the hills and, as the article you found describes, they cut trees in a volume large enough to fill a ship. The measuring pits even had a local name: lua na moku ‘iliahi . As a consequence of years of unpaid hard labor, people began to rip out young trees in the hopes that their children might escape enslavement to the sandalwood trade. By 1840, trade dwindled.

From an eyewitness account:

“On one occasion we saw nearly two thousand persons, laden with fagots of sandalwood, coming down from the mountains to deposit their burthens in the royal store houses, and then depart to their homes–wearied with their unpaid labors, yet unmurmuring in their bondage. In fact, the condition of the common people is that of slaves; they hold nothing which may not be taken from them by the strong hand of arbitrary power, whether exercised by the sovereign or a petty chief.” -April 18, 1822

Source:

James Montgomery, ed., Journal of Voyages and Travels by the Rev. Daniel Tyerman and George Bennet, Esq. 2 Vols. (London: F. Westley & A.H. Davis, 1881) I:415.

There have been attempts over the decades to restore the population of sandalwood, but most efforts failed until the 1990s, when Mark Hanson collected seeds  of native sandalwood and other native tree species, and began the Hawaiian Reforestation Program. His efforts are ongoing. The trees remain vulnerable (due to land-clearing to raise cattle, and harvesting for use in essential oils and incense), and are listed as endangered on the IUCN Red List.

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Searching for sweetgrass

My book club is reading Robin Kimmerer’s Braiding Sweetgrass. Do you know anywhere I could go to smell and see the plant? Might some be planted outside the Burke Museum, or at the Center for Urban Horticulture? What are local native uses of the plant?

 

illustration of sweetgrass
[from The Grasses of British Columbia by William A. Hubbard] Photo: illustration by Frank L. Beebe

In the context of Robin Wall Kimmerer’s book, sweetgrass probably refers to the plant whose scientific name is Hierochloe odorata. It grows in limited locations in Washington State. We do not have it here at the Center for Urban Horticulture. It is unlikely to have been planted around the Burke Museum, given its preference for marshy areas. Most of their plantings are at the edges of the parking lot. However, you could call and ask. You might be able to smell sweetgrass in woven items made from the plant, though the fragrance might not be as intense as the odor of the living plants.

The trouble with common names is that they may refer to different plants (not only a different species, but even a different genus and family), depending on what region of the world one inhabits. Kimmerer, who lives in Syracuse, New York, is a member of the Potawatomi tribe. The name she uses for sweetgrass is wiingashk ᐐᓐᑲᔥᒃ᙮, which is Ojibwe, a language that is linguistically similar to Potawatomi.

To give just one example of the potential for confusion, there is a Pacific Northwest ‘sweetgrass’ used by basket weavers on the Olympic Peninsula which is Schoenoplectus pungens, also called chairmaker’s clubrush or common three square, an entirely different genus in the sedge family (not in the grass family). The book does not mention its use for incense or fragrance, but the species name (pungens) does suggest it has an aroma, though possibly a sharp but not a sweet one. [source: From the Hands of a Weaver: Olympic Peninsula Basketry through Time, University of Oklahoma Press, 2012]

Examples of Hierochloe odorata’s use in the Pacific Northwest:

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Is Diabolo ninebark a PNW native?

I am wondering if Diabolo ninebark is a native to the Pacific Northwest. I know it is a hybrid.

 

There are several components to consider here. Physocarpus opulifolius ‘Diabolo’ is a cultivar (a cultivated variety, selectively bred for certain characteristics that differ from the plain species) of a ninebark species that is native to eastern North America. A hybrid is produced through sexual reproduction between plants of two different species or varieties, either in the wild or in cultivation. This blog post describes some potential ramifications of using ‘nativars’ (quasi-native plants) such as ‘Diabolo.’ Cultivars are not natives, but that isn’t necessarily a reason to exclude them from your garden. This link provides clear explanations, excerpted here:

“When the native plants in our yards are locally-sourced and locally-adapted, their DNA can make a positive contribution to the survival of wild plant populations. The adaptive genetic diversity they share is important because it allows native species to persist despite the rapidly changing conditions of our modern environment. […]

“When the plants in our yards are cultivars of native species, their genetic makeup is the result of artificial rather than natural selection and they possess little genetic diversity. The offspring of cultivars crossed with native plants are called hybrids. […] Once the DNA from cultivars of native plants makes it into wild populations, there is no way to dispose of it. The new DNA affects the ability of wild native plants to survive and has ramifications for all the species that interact with the native plant as well. Studies have shown that, in some cases, cross-pollination with cultivated varieties resulted in the loss of the wild relative. […]

“Sterile cultivars of native plants are benign, they can’t cross-pollinate with their wild relatives, so they pose no risk to wild plant populations. When cultivars are beneficial to ecosystems, they are good. For example, plant breeders are working to create disease-resistant cultivars of native tree species that have been hit hard by non-native invasive plant pathogens. If done with care, it is possible that such cultivars could be used to intentionally spread beneficial DNA into wild plant populations and help restore those species. […]

“When cultivars are harmful to ecosystems, we must ask whether the benefit to people outweighs the risk to native plant species and pollinator populations. Cultivars of plants aren’t just bred for ornamental use, but for food and medicinal value as well.”

If you want to grow a species of ninebark that is native to the Pacific Northwest, consider Physocarpus capitatus.

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Ipomoea pes-caprae on a Brazilian beach

Can you confirm the identity of this plant growing on the northeastern coast of Brazil? I’m told it is called batata-da-praia, or batata-do-mar (beach or sea potato). Does that mean it’s edible?

 

 

This is Ipomoea pes-caprae, probably the subspecies brasiliensis, given the location. It is pantropical, found along the beaches of the tropical regions of the Atlantic, Pacific, and Indian oceans. (It produces air-filled seed capsules that float and drift in water, contributing to its wide distribution.)

Common names in English include railroad vine (referring to the ‘tracks’ created by its stoloniferous habit of spreading along the ground’s surface, sometimes over 100 feet), goat’s foot (translation of the botanical species name, given for the hoof-like leaf shape), beach morning glory (since it is in the morning glory family, Convolvulaceae), and beach hops (because of the vining habit).

Cooked roots, stems, and leaves have been eaten in small quantities as a famine food, and it has a history of medicinal uses. However, it is not a major food source like its cousin, the sweet potato (Ipomoea batatas). Toxic Plants of North America (Burrows & Tyrl, 2013) considers this species of Ipomoea to be of toxicological concern.

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Liriope lawn in the Pacific Northwest

A client, who planted a small Liriope “lawn” heard from a different landscape professional that this plant does poorly in our climate because we don’t have enough summer humidity. I haven’t used it a lot in my designs, and haven’t grown it in my own yard, but have considered it a tough and versatile plant. Is it true it does poorly here? (Why have I not heard this before?)

They used small plants for their lawn. I’ve suggested they give it two years since I think it is an interesting idea. We all realize it won’t take the kind of foot traffic regular turf will take. What do you think?

 

My personal experience with Liriope is not altogether positive. It pokes along in partial shade in my garden, looking rather ratty most of the time. It may be that I don’t provide it with enough water to make it happy. It’s hard to say, based on one person’s garden, whether the same will hold true in other soils, and other light and irrigation patterns. I don’t see it planted in large public spaces, or even in large quantity in home gardens in our area. And I agree with you, it’s not a turf substitute–its common name ‘lilyturf’ is a misnomer, as it’s not a lily and neither is it a turf plant.

Missouri Botanical Garden’s information about two commonly grown species suggests it does well in the South (where it’s humid in summer).

Liriope is included in Perennials: The Gardener’s Reference by local authors Susan Carter, Carrie Becker, and Bob Lilly (Timber Press, 2007). There are several species. Liriope muscari forms clumps a foot and a half wide; Liriope spicata “spreads rapidly by underground stems and will cover a wide area; it is therefore not suitable for edging but is excellent for groundcover.” It grows 8-12 inches tall by a possibly infinite spread, meaning it can be aggressive if the conditions are right. The authors say all Liriope flowers best in sun, and prefers moist, well-drained soil though it may be drought-tolerant once established. “Ragged with neglect” accurately describes the way my own plants look, so perhaps I’m just negligent. The authors say it may be cut back to the ground in spring before new growth begins, but “if there’s no winter damage, do not cut back.”

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Camphor wood chips and safety

A friend gave me a small bag of camphor wood chips. I have them in my car and like the smell. Someone told me that camphor can be toxic. Is is toxic to breathe or to burn, to humans or to plants? Is it safe to just keep in my car and enjoy the aroma?

 

Cinnamomum camphora (source of camphor wood) is in the Laurel family. According to Toxic Plants of North America (Burrows & Tyrl, 2013), “few toxicologic problems have been associated with the genus. However, when a camphor tree was planted in an aviary, 49 budgerigars died within 24 hours, apparently from its noxious fumes.” As implied by its common name [camphor tree], all parts of the tree contain camphor. The intensity is greater in the leaves than in the wood. The tree’s toxic properties have been known since the late 1800s, and most exposures are non-fatal and involve accidental ingestion of liniments that contain the oil from the plant. When inhaled, camphor is usually a mild irritant (perhaps not so mild at all if you are a bird!) and nervous system stimulant. It also contains low levels of toxic alkaloids.

If you wish to err on the side of caution, I would suggest not breathing the fumes, burning the wood, or using it in the garden (unless you are trying to suppress weeds, though the tree itself is considered a weedy species in some parts of the world, such as Australia). As you probably know, people have used camphor-based preparations in herbal and traditional medicine.

About medicinal uses and associated risks

About the tree

About the wood

The article “Camphor—A Fumigant during the Black Death and a Coveted Fragrant Wood in Ancient Egypt and Babylon—A Review,” by Weiyang Chen, Ilze Vermaak and Alvaro Viljoen, offers a historical perspective, and does mention that the tree may have some phytotoxic/allelopathic properties as well (toxic to other plants).

Abstract:
“The fragrant camphor tree (Cinnamomum camphora) and its products, such as camphor oil, have been coveted since ancient times. Having a rich history of traditional use, it was particularly used as a fumigant during the era of the Black Death and considered as a valuable ingredient in both perfume and embalming fluid. Camphor has been widely used as a fragrance in cosmetics, as a food flavourant, as a common ingredient in household cleaners, as well as in topically applied analgesics and rubefacients for the treatment of minor muscle aches and pains. Camphor, traditionally obtained through the distillation of the wood of the camphor tree, is a major essential oil component of many aromatic plant species, as it is biosynthetically synthesised; it can also be chemically synthesised using mainly turpentine as a starting material. Camphor exhibits a number of biological properties such as insecticidal, antimicrobial, antiviral, anticoccidial, anti-nociceptive, anticancer and antitussive activities, in addition to its use as a skin penetration enhancer. However, camphor is a very toxic substance and numerous cases of camphor poisoning have been documented. This review briefly summarises the uses and synthesis of camphor and discusses the biological properties and toxicity of this valuable molecule.”

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Jerusalem artichoke facts

Is Jerusalem artichoke native in our region? What is its connection to Jerusalem? Did local Native American tribes have uses for it? I grow it, and friends have suggested that it is a good alternative to potatoes for people with diabetes because it has a lower glycemic index. Have you heard anything about that?

 

Jerusalem artichoke or sunchoke (Helianthus tuberosus) is commonly found across most of North America, according to its plant profile on the website of the U.S. Department of Agriculture Natural Resources Conservation Service.

The plant’s common name mistakenly suggests it might be from Jerusalem, but the name probably evolved through faulty hearing, either of the Italian word for sunflower [girasol] or of Ter-Neusen [now spelled Terneuzen], where a 17th century Dutch gardener began distributing the plant throughout Europe. Another theory is that pilgrims in North America believed this would be a wonderful new food source in their “New Jerusalem.” [source: D. R. Cosgrove et al. Jerusalem Artichoke in Alternative Feed Crops Manual, University of Wisconsin and University of Minnesota Extension, accessed online November 1, 2014). For an in-depth exploration of the plant’s name and its uses, see the chapter in The Sunflower by Charles Heiser (University of Oklahoma Press, 1976).

The book Native American Food Plants: An Ethnobotanical Dictionary by Daniel Moerman (Timber Press, 2010) mentions uses of the plant’s tubers by numerous tribes, but not ones in the Pacific Northwest. Some tribes, such as the Chippewa, traditionally used the tubers raw, while others like the Dakota boiled them (and noted that their overuse caused flatulence, about which more later!). Several tribes (Huron, Lakota) only used the tubers during periods of famine to fend off starvation. The Ladybird Johnson Wildflower Center’s Native Plant Database says that Helianthus tuberosus “was cultivated by Native Americans of the Great Plains and has spread eastward. The edible tuber is highly nutritious and, unlike potatoes, contains no starch, but rather carbohydrate in a form that is metabolized into natural sugar. In 1805 Lewis and Clark dined on the tubers, prepared by a native woman, in what is now North Dakota.”

We recommend consulting a healthcare professional to find out if Jerusalem artichokes would be a better choice than potatoes (which contain starch) for someone with diabetes. Helianthus tuberosus, like other sunflowers, is in the Family Asteraceae. It contains a polysaccharide (a type of carbohydrate) called inulin. While it is true that some potatoes have a high glycemic index, cooking them alters it, and they can still be part of a balanced diet.

Another thing to consider is that not everyone has an easy time digesting the inulin in Jerusalem artichokes. Although culinary use of sunchokes has become quite a trend lately, some chefs will not serve it in their restaurants, according to Bon Appetit magazine (article by Andrew Knowlton, February 19, 2013) and the tubers have acquired the unhappy nickname ‘fartichoke.’ The Plants for a Future online database (www.pfaf.org) refers somewhat more delicately to inulin intolerance (which may be genetic): “[inulin] tends to ferment in their guts and can cause quite severe wind.”

As you probably know, Helianthus tuberosus prefers sun, and can reach ten feet in height. You can plant small tubers in early to late spring. It is an easy plant to grow, and in some cases it proliferates like a weed. It might be good to confine it to one part of your garden if you can.

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Growing Coleus from cuttings

I have taken cuttings from my Coleus plants and rooted them in water. They now have about 2 inches of fine roots growing. I’m planning to overwinter them. Should I pot them up in potting soil now?

 

According to Coleus: Rainbow Foliage for Containers and Gardens by Ray Rogers (Timber Press, 2008), growing Coleus from cuttings (rooting them, as you did, in water) is a fine way to propagate more plants. The cuttings will survive for weeks or even months in nothing but water, and with soluble fertilizer, this time could even be extended.

However, since you want plants which may eventually live somewhere other than the windowsill or counter, Rogers recommends removing the cuttings from the water when roots are an inch or two long, and planting them in growing medium. This is because roots which are produced in water are less sturdy, so making a transition to growing medium helps the plant develop. (Long water roots are easily damaged if pressed too hard when potting them up.) As for the potting medium, even garden soil can be used if it is not heavy clay and does not dry out. Since you are going to keep your plants indoors over winter, you may want to use purchased potting mix which has an open structure (drains well but will not dry out too fast). The mix might include bark, coir, perlite, pumice, or other ingredients. The author has a preference for vermiculite, but be careful to wear a dust mask when handling any fine materials; you definitely don’t want to get particles in your lungs.

Once you’ve potted the cuttings, keep the medium moist but never soggy, and keep them humid (using a mister, for example). Cuttings need bright light but not direct sun, and should be kept at about 70 degrees. If room temperature drops below 50, you may want to set the pots on a heating mat. You don’t need to add fertilizer while the cuttings are getting established. You can move the cuttings into larger pots once they’ve developed a strong root system (at least a week).

Other tidbits of information that may be useful:

  • Cuttings can be taken from any piece of stem on the parent plant, but it’s best to choose stems which are neither the youngest nor the oldest growth.
  • Cuttings taken from the sunnier side of the plant have firmer tissue and may root more strongly than cuttings from the shadier side, but they will also need consistent humidity and protection from intense sun while rooting.
  • Cuttings will look like the parent plant if the parent plant is a genetically stable cultivar, but some cultivars (especially with pale pink in the center of their leaves) are more prone to reverting or sporting.
  • Once night temperatures outdoors are above 60 degrees, it should be safe to move your plants outdoors (but it’s always a good idea to harden them off gradually beforehand).
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