I was talking to a friend the other day about making a Strawberry/Rhubarb pie. We were discussing whether the stalks of my rhubarb plants were big enough yet since I’ve only had them a couple of years. What really caught my attention was when she said “just be sure you don’t eat the leaves because they are poisonous”. I did not know that. It made me wonder what other plants in my yard are toxic so I did some research. I discovered that several of my beautiful perennials fall into the ‘poisonous’ category. Most of these plants are toxic only if ingested but some of them can also cause skin irritation. It is good information to know in case you have children or animals around. Six of the most common plants I found are:* Rhubarb - The toxin concentrated in rhubarb leaves and roots is a form of oxalic acid (a skin irritant) that, when ingested in large quantities, is poisonous to humans.
Toxic part: Leaf blade
Symptoms: Large amounts of raw or cooked leaves can cause convulsions, coma, followed rapidly by death.
* Chrysanthemum, Garden Mum - Garden chrysanthemums can be a severe skin irritant. It’s possible to develop contact dermatitis after extended exposure to mums. So even if you haven’t had a reaction before, it’s good to be aware of the potential for a problem beforehand.
Toxic part: Leaves, stalks, flowers.
Symptoms: skin reddening, scaling, blisters.
* Hydrangea - Poisoning from eating the flower buds has occurred. Sensitive individuals may develop contact dermatitis from handling the plants.
Toxic part: Leaves, flowers, bark.
Symptoms: stomach pain, nausea, vomiting and sweating.
* Oleander -These plants are highly toxic. To avoid possible poisoning when working with Oleanders, wash hands and arms thoroughly when finished working with the plant. The toxin is mostly contained in the sap which is clear to slightly milky colored, and sticky.
Toxic part: Leaves, branches.
Symptoms: Extremely poisonous. Affects the heart, produces severe digestive upset and has caused death.
* Rhododendron & Azalea -All parts of Rhododendron and Azalea plants are extremely toxic if ingested. Seek medical help immediately.
Toxic part: All parts.
Symptoms: Produces nausea and vomiting, depression, difficult breathing, prostration and coma. Can be fatal.
* Wisteria - The entire plant, also known as a kidney bean tree, is toxic, though some say the flowers are not.
Toxic part: Seeds, pods
Symptoms: Mild to severe digestive upset. Many children are poisoned by this plant.
For more information, there is a good reference Chart reprinted from materials provided by the Texas State Department of Health and the National Safety Council available at
http://plantanswers.tamu.edu/publications/poison/poison.html.