When 'Natural' Is Definitely Not Safe

By Ruth Kava — Jun 06, 2017
The meme that "natural is safe" can get you into trouble in many ways. It's one that's appropriate at this time of year, when gardens and flowers are on our minds, since some plants are naturally deadly. Here are a few commonly found in our gardens and often available from nurseries, as well.
Foxglove Flowers

Last weekend when walking through our local garden shop I found some really beautiful flowering plants for sale — ready to be installed in one's spring and summer garden. One of the showiest was the Foxglove (Digitalis purpurea). What I didn't see, however, was any notice that this plant could be cardiotoxic — after all, this is the original source of the medication digoxin. So if you don't eat it or drink tea made from it, you're ok. But children and pets are known to nibble on things they shouldn't, so information about what isn't a smart snack choice could be useful to people planning a garden, or just trying various "natural" plants and products. Here's a few known to be problematic and their potential effects.

Nerium oleander: Also called oleander, rose bay and rose laurel. Oleander is used as a freeway divider in northern California, where it adds color and screens the traffic lanes from each other. All parts of the plant are poisonous — cattle have died after consuming its leaves. This plant contains a cardiac glycoside — appropriately named oleandrin — which can cause cardiac irregularity. 

Oleander credit: Shutterstock

Convallaria majalis: Lily of the valley. Like oleander, this plant contains cardiac glycosides and also saponins which can cause gastrointestinal damage. Although much admired for its beauty and fragrance, and widely used in plantings, this is another one to avoid consuming.

Lily of the Valley Credit: Shutterstock

Aristolochia spp: Dutchman's Pipe. This is a large genus, containing hundreds of species. These plants contain aristolochic acid which is toxic to the kidneys. Found in some folk remedies, a weight-loss nostrum containing it caused kidney failure, kidney cancer or the need for kidney transplantation in over 100 women. We wrote about it here. Much prized for its drought - and shade-tolerance, this plant is widely available from nurseries.








Dutchman's Pipe Credit: Shutterstock

Dieffenbachia spp: Dumb cane. This popular house plant requires little light and thus can thrive in dark corners and corridors. Unfortunately, it comes with a high content of oxalic acid, which can lead to nausea and vomiting as well as blistering of the mouth and throat. It's also toxic to dogs and cats.

Dieffenbachia Credit: Shutterstock

These are just a few of the many plants that pose a "natural" threat to health. Grow them if you wish, and enjoy their beauty — just remember the downside!