My Poison Garden

by Linda S Lange

It all began innocently enough, I suppose.

I mean, it’s not as if I sat down with my garden journal one morning and said, “I believe I’ll plant a poison garden over there…with some foxglove, say, and a bit of aconite for that lovely blue color.” Truly, I don’t remember how it started. But Agatha Christie may be to blame. Miss Marple, probably.

I’ve been a mystery reader for as long as I’ve been a gardener: Nancy Drew under the Christmas tree and puddling in the tomato plants with my grandmother. The two just grew up together, mysteries and gardens—organically, as it were. But it wasn’t until I had my own garden in Denver that I began to notice that some of the poisons in those mystery stories—especially those with a gardening connection—came from plants that I was growing in my backyard! Innocently enough, I probably chose them for the lovely flowers, or perhaps because I subconsciously recognized the name from a story.

After awhile, however, it became more deliberate—choosing and cultivating those specimens that carried a sinister back story, and studying the properties of seed or leaf or root, often with my fellow Rocky Mountain Unit members. Reading Susan Wittig Albert’s China Bayles mysteries and, of course, Amy Stewart’s Wicked Plants. More recently, with the HSA’s Herbal Fiction Book Clubs, Sarah Penner’s Lost Apothecary and A is for Arsenic: The Poisons of Agatha Christie by Kathryn Harkup. It’s such a delight to learn that something I’ve been growing for years has a dark side!

Eventually, it became a point of mischievous pride. “Did you know those morning glories are poisonous?…Or those lovely lilies of the valley?”  Amusing to watch the innocent garden visitor step back and look around carefully.

“Of course you want to wait until the elderberries (Sambucus) are fully ripe, and even then…Take care if you brush against the rue (Ruta graveolens), it’s sometimes an irritant. Rhubarb (Rheum) leaves, of course, but did you know about Caladium and elephant ear (Colocasia)?…The yew trees (Taxus spp.) are actually my neighbor’s.”

“Let me show you the fall crocus! No saffron from this one. Colchicum autumnale is a whole different family and very bad news in the kitchen!”

The thing is, so many of our common garden plants can be “irritating, obnoxious, or downright deadly,” to borrow a phrase from Amy Stewart. What’s been the most fun about deliberately cultivating known sources of poison is learning about them myself and sharing the message that our gardens are not always as innocent as we might think. Often it’s just a matter of the dose or preparation that differentiates a health benefit from something more deadly – like the heart medicine digitalis from foxglove or cancer treatment, Taxol, from the yew.

Sound plant identification is critical, of course. My initial source is usually Thomas J. Elpel’s Botany in a Day: The Patterns Method of Plant Identification, An Herbal Field Guide to Plant Families of North America (2013).  And it’s fair to say – again – that I’m a gardener.  I’m growing these things for fun and not for use! I drink coffee from the supermarket, and rarely – if ever – tea from my garden.

Photo Credits: 1) Larkspur (Delphinium sp.) in the foreground as a stand-in for wolf’s bane (Aconitum sp.); 2) Datura sp. and Ipomoea sp.; 3) Black elderberry (Sambucus sp.), elephant ears (Colocasia sp.), and lily of the valley (Convallaria majalis); 4) Down the garden path; 5) Author with morning glories. All photos courtesy of the author.

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Linda “Lin” Lange is a gardener, avid mystery buff, and incoming president of The Herb Society of America. So far, at least, she doesn’t think anyone has been poisoned in her Denver garden, but several visitors have been observed to step back a bit when the plants are identified and her husband is very cautious about harvesting.