The Poison Garden

We all know the garden can be a place for all kinds of poisons, from weed killers to weapons to plants. Be sure and check out Amy Stewart's Wicked Plants: The Weed That Killed Lincoln's Mother & Other Botanical Atrocities (Algonquin)/ I've written about poisonous plants in the Mystery Readers Journal, but Stewart takes it several steps further. Be sure to add this to your Garden Book Collection.

Anyone who reads Agatha Christie, the Poison Queen, is aware that Foxglove is poisonous, and of course, Castor Beans. What else grows in the garden? Hemlock, yes, Lilies, yes, Monkshood, yes. Besides poisonous plants there are those that cause hallucinations and cardiac arrest. Aconite, Datura, and let's not forget Oleander. Don't put your marshmallow on an Oleander branch. Every part of the oleander is poisonous. Drying the plant doesn't help, not to mention that the crushed seeds of the oleander have been used to commit suicide in India.

Look around your garden and see if you have any of these--or design your own poison garden, if you're so inclined. Following is a list of some poisonous plants you might find in the garden.

Foxglove: Digitalis: Throw a few leaves in a salad, eat and die. Agatha Christie used this in one of her novels.
Yew: Taxus bacata. The berries are lethal.
Cherry Laurel: These looks like regular cherries but are quite lethal. Interesting to note that the edible cherry and the laurels all share the same family name (Prunus). FYI: The Portuguese Laurel (Prunus lusitanica) has cyanide compounds in its leaf. Don't burn it!
Aconitum: Monkshood, Wolfsbane, Leopard's bane
Arum: Cuckoo pint

Buttercups
Colchicum: The autumn crocus. Can be fatal if eaten
Convallaria: Lily of the Valley
Christmas Rose
Cytisus: Broom: All parts can be fatal if eaten.
Daphne: Shrub grown for its beautifully scented flowers. Can be Fatal
Delphinium: All parts highly toxic - can be fatal if eaten
Difffenbachia: Dumb Cane: Very common houseplant. Keep away from cats & puppies
Euphorbia
Gloriosa superba: The beautiful Gloriosa Lily!
Laburnum: Beautiful golden rain flowers. Can be fatal if eaten
Lantana: Now very popular in the summer border or planted pot!
Nerium: A beautiful conservatory plant
Phytolacca: The poke weed
Ricinus communis: Castor Oil Plant. Not to be confused with Fatsia.
Taxus: A hedge favorite.
Veratrum: The false Hellebore.
Bleeding Heart
Capsicum species: Red Pepper, Cayenne Pepper
Chrysanthemum: Daisy, Feverfew, marguerite
Daffodil
Deadly Nightshade: Atropa Belladonna. Leaves and Berries are toxic.
Water Hemlock (Cicuta): Called the most violently toxic plant in Northern America

Hydrangea
Hyacinth
Iris
Jasmine
Jimson Weed: First plant poisoning death credited to Jimsonweed. Jamestown, VA  settlers used jimsonweed to poison British soldiers. Also called Devil's Trumpet, Angel's Trumpet, Stinkweed, Locoweed, Hell's Bells
Jonquil
Lathryus: Sweet Pea
Lily of the Valley. Be sure and wash up after touching it.
Lobelia
Mistletoe
Narcissus
Rhubarb: (leaves)
Tulips
Water Hemlock
Wisteria
Laurels, Rhodendrons and Azaleas

Of course, many different mushrooms

And a few others: Wild clematis (old man's beard) was once used by professional beggars who rubbed its sap into scratches to make temporary weeping ulcers.
Laburnum causes convulsions, vomiting and foaming at the mouth
Strychine (Quaker's Button).. well we all know about this one.
Henbane
Daphne (berries, bark and sap are potent)
Phytolacca: Pokeweed
Veratrum: False Hellibores

Poison Ivy and Poison Oak, but you know about those. 

Not in my garden: Manchineel (Hippomane Mancinella): Native to Florida, the Bahamas, the Caribbean, Central America & South America. Name means "little apple of death." Entire tree is toxic to humans and animals. Don't stand below this tree, as the sap could cause blindness and respiratory problems.

One of the non-growing poisonous elements of a poison garden would be cocoa bean hulls, often used for mulch. Although the cocoa bean hulls smell terrific, they're not good for dogs. I've always used cocoa bean hulls mulch in my own garden, and I've been lucky with all my dogs so far. None seem to be interested in the mulch, probably because it smells too good and not like skunk. The theobromine in the hulls can lead to vomiting in dogs. 

So have a look around the garden and see how many poisonous plants you have. There's a proverb that says, "A Book is Like a Garden carried in your Pocket." If it's a mystery, it must be a poisonous garden.

Where to visit a Poison Garden:
San Francisco's Conservatory of Flowers is hosting an exhibit Wicked Plants: Botanical Rogues & Assassins"  It's all about poisonous plants and their place in history. Exhibit is named for Amy Stewart's book Wicked Plants. Through October 30, 2011.
Alnwick Castle in the UK has a poison garden, definitely worth visiting, but don't touch the plants.
The Muenscher Poisonous Plants Garden (Cornell) in Ithaca.
The Brooklyn Botanical Gardens has a poisonous garden exhibit.

Two years ago in the UK, a 66 year old gardener found Devil's Snare (Thorn-apple) in his garden. This mystery plant is used by Amazonian tribes to poison their darts. These plants turn up occasionally in waste and cultivated ground, having been brought to the U.K. in bird seed.