Gardening Poisonous Plants

Touch-me-not Plants

Some plants have the ability to cause contact dermatitis (an unpleasant skin reaction).

Sometimes just simply brushing against the plant will do it, but in other cases, you actually have to bruise the plant or snap off a leaf or stem before a reaction will occur, because it’s contact with the sap that is harmful.

Note that in some cases, dermatitis will only occur if the skin is exposed first to the sap and then to the sun. This is called photodermatitis or phototoxicity. With these plants, there is therefore less risk of a reaction on a cloudy day.

Note too that sensitivity varies greatly from one individual to another: what can send one person to the hospital (and yes, that can happen!) may have no effect on another. But since you never know whether you’re sensitive or not, please wear gloves and long sleeves if you have to handle the following plants.

Buttercups* (Ranunculus spp.) can cause photodermatitis in sensitive individuals. Photo: pixbay.com
Dogbane (Apocynum androsaemifolium). Photo: Dcrjsr, Wikimedia Commons
Gas plant* (Dictamnus albus). Photo: http://www.specialplants.net 
Hogweeds* (Heracleum spp.). Photo: http://www.gardentags.com
Nettles (Uticaria spp. and Laportea spp.). Photo: Uwe H. Friese, Wikimedia Commons.
Poison-hemlock* (Conium maculatum). Photo: homeopathyonline.org.uk
Poison ivy (Toxicodendron radicans). Photo: meltonwiggins.com
Rue* (Ruta graveolens). Photo: http://www.qjure.com
Spurges (Euphorbia spp.). Photo: http://www.crocus.co.uk
Velvet bean (Mucuna pruriens). Photo: urbol.com
Wild Parsnip* (Pastinaca sativa). Photo: lcinvasives.org

*Plants causing photodermatitis.

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

1 comment on “Touch-me-not Plants

  1. Again, as you know, the list could continue. Poison oak is similar to poison ivy. Some are allergic to primula, and many are allergic to some of the grevilleas!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: