Gardening Answers Knowledgebase

Question:

I know that Brugmansia has toxic and intoxicating properties. I heard a story about a railway carriage in Europe that was filled with the Brugmansia flowers. When the doors to the carriage were closed, the fragrance of the blooms caused the passengers to lose consciousness, and their valuables were stolen. Plausible, or urban legend?

Answer:

Brugmansia, like the related solanaceous plant Datura, contains tropane alkaloids throughout the plant, including the seeds and flowers. One of these alkaloids is scopolamine. There are many tales of "Devil’s Breath," a processed form of scopolamine (as powder), or scopolamine-rich seeds being used by criminals in various parts of the world to drug their victims into unconsciousness. There is an article in The Guardian (September 2, 2015) which suggests it's unlikely that this substance would have been used to "zombify" travelers in Europe. There are, however, travel security warnings from the U.S. State Department about its use by criminals in Ecuador and Colombia.

A scientific article, "Volatile compounds emitted from flowers and leaves of Brugmansia X candida (Solanaceae)" (G.C. Kite and C. Leon, in Phytochemistry, 1995) states that volatile tropane alkaloids could not be detected in the fragrance of either flowers or leaves; the main volatile organic compounds emitted by the flowers are terpenoids, benzenoids, and indole. Those compounds can cause headaches but it seems unlikely they would act like a sedative.

The book Plant Intoxicants by Baron Ernst von Bibra (Healing Arts Press,1995) describes use of Datura seeds by criminals in India to knock out their victims. There are many traditional medicinal uses of Brugmansia among the indigenous tribes of Colombia, but the hallucinogenic effects are especially frightening. One tribe describes the pleasant scent of the flowers but warns that the plant is inhabited by an evil spirit and all who sit at the foot of the tree "will forget everything." (Source: Plants of the Gods, Richard Evans Schultes, Healing Arts Press, 2001). However I cannot find any confirmation for your colorful story of a train carriage full of drugged passengers among the Brugmansia flowers.

Question:

I am growing goji berry plants in my garden. I was hoping their growth habit would be more upright but they are sprawling wildly. Do you have suggestions for training them? Should I be concerned that they might become invasive?

Answer:

Susanna Lyle's book Fruit & Nuts (Timber Press, 2006) says these shrubby vines are short-lived, peaking in berry production at about 5 years of age and typically living for 8 years or so. She advises planting them near a fence or trellis so that they can be trained up it; some sprawling is to be expected. Utah State University Extension's October 2015 article, "Goji in the Garden," offers general cultural information (while mentioning that the plant is a weed in some areas).

Lycium barbarum (goji, also called wolfberry and boxthorn) can be invasive (or at least aggressive) in some areas. An article by Vern Nelson in The Oregonian (August 17, 2008) mentions this tendency, and suggests containing them in a 4 by 5-foot square support structure. Be aware that "wolfberries take root wherever they touch the ground." This is worth bearing in mind, as is the fact that Lyle's book says "the extensive root system can help stabilize banks," which one could interpret to mean that removing unwanted plants might be a fair bit of work!

Suckering roots are only one way the plant spreads; seeds are another. Goji berry (boxthorn) is the "Plant of the Month" in the Whatcom County Master Gardeners Weeder's Digest from August 2006. Author Cheryll Greenwood Kinsley notes that when the plant was first introduced in Europe, people weren't enamored of the fruit but birds were, and now "the shrub has naturalized in Britain and is listed as a noxious weed on two continents and in at least some parts of several states, including Montana and Wyoming." She recommends keeping the birds away from it to discourage its spread.

Question:

Slowly but surely, what's left of my untended lawn is being overtaken by a small weed with fan-shaped leaves. It reminds me of a tiny Lady's Mantle. What is it, and is there any hope of getting rid of it without herbicide?

Answer:

Your description sounds like Aphanes australis, whose common name is slender parsley-piert. It thrives in dry, exposed, or barren soils. North Carolina State University's Turf Center describes cultural control methods:
"Winter annual broadleaf weeds germinate in the fall or winter and grow during any warm weather, which may occur in the winter, but otherwise remain somewhat dormant during the winter. They resume growth and produce seed in the spring and die as temperatures increase in late spring and early summer. They quickly invade thin turf areas especially where there is good soil moisture. Shade may also encourage growth. Many have a prostrate growth habit and are not affected by mowing. A dense, vigorous turf is the best way to reduce the encroachment of winter annual weeds. First, select adapted turfgrass cultivars for your area and then properly fertilize, mow, and water to encourage dense growth."

It sounds like lawn renovation might be a good idea. If the parsley-piert has intense competition from a happily growing lawn, it will not thrive. Seattle Public Utilities has good resources on lawn care.

Question:

There's a climbing vine in my garden which has hydrangea-like flowers. I have lost the tag, and don't know if it is Hydrangea petiolaris, or Schizophragma hydrangeoides--how can I distinguish one from the other?

Answer:

There is an article in Arnoldia (the journal of the Arnold Arboretum at Harvard University) from July 24, 1933 which explains that the two plants are related, but the flower 'petals' (which are actually sepals) surrounding the center are distinct:
"In Hydrangea petiolaris this encircling tiara is composed of greenish white flowers, each one made up of four rounded sepals. In Schizophragma hydrangeoides these showy sepals are a purer white and they are borne singly rather than in fours."

University of Arkansas Extension also says that Schizophragma "differs in flowering time (after climbing Hydrangea) and in the fact that it protrudes less from structures."

There is another less commonly grown climbing Hydrangea, Hydrangea integrifolia, an evergreen that grows to 40 feet tall and 20 feet wide. Its flower buds look almost like those of peonies, and its leaves are elongated and glossy.

Question:

Is there such a thing as a red aloe? Or an aloe that gets that color when planted in a sunny spot? I am especially interested in any that have a reddish tone. Do any of these survive the winter outdoors here in the Pacific Northwest?

Answer:

The most famously red aloe is Aloe cameronii. In her book Succulent Container Gardens (Timber Press, 2010), Debra Lee Baldwin mentions several species that change color in sun:
"Aloes that turn color when given full sun include Aloe cameronii (crimson), Aloe buhrii (orange), and Aloe taurii and Aloe dorothaea (bright red). Softball-sized Aloe nobilis, which forms dark green rosettes with wedge-shaped leaves toothed with white or yellow prickles, turns shades of red-orange."
Baldwin’s book also includes "design-oriented plant lists" with guidance about color.

In our climate, most aloe species will need to be sheltered over the winter in a greenhouse. One local nursery, Desert Northwest lists a couple of winter-hardy (or almost-hardy) aloes, but they are not the ones noted for their red foliage.