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Gardening Articles

Our most recent article, as published in Mountain Democrat


By: Pauline Atkins, UCCE Master Gardener of El Dorado County

“I wondered why it had to be so poisonous. Oleanders could live through anything, they could stand heat, drought, neglect, and put out thousands of waxy blooms. So what did they need poison for? Couldn’t they just be bitter?”

That quote is from the novel, White Oleander by Janet Fitch, where a character kills her cheating boyfriend with a highly poisonous elixir made with white oleander petals. Spoiler alert: the jealous woman is sentenced to life imprisonment for murder.  

The invasive evergreen, Oleander, Nerium oleander, originating in the Mediterranean Basin, is one of the deadliest in our region. It is not a G-rated plant!  Everything about this plant is dangerous and poisonous: from the lance-shaped leaves’ sharp tips, to its brightly colored flowers, treelike branches, roots, sap, and even its bark.

If ingested, or even touched, it can be harmful, and possibly lethal. Most highly at risk are children, pets, and livestock. The only saving grace is that the leaves and flowers are very bitter. This generally does not encourage munching, and is unpalatable to humans and most animals.

The plant contains cardiac glycosides. The main one is called oleandrin. If ingested, it can cause myriad life-threatening symptoms. They include arrhythmia (irregular heartbeat), dizziness, diarrhea, and vomiting.  Touching the leaves can cause irritation to the skin, with the sap of the plant potentially causing skin rashes, itchiness, and blurred vision. Take care when pruning or handling the plant by wearing protective gloves, outerwear, and safety glasses.

Various sources have indicated that pruned leaves and branches should not be thrown on your compost pile. Do not burn clippings because the smoke can be toxic. Your best option for safe removal is to bag it and take it to the dump.

There have been numerous urban legends about Oleanders. The best-known story is about a group of Scouts that used Oleander twigs to spear and roast hot dogs over the campfire. Tragically, they were poisoned, and the entire group succumbed. True or not, it serves as a strong cautionary tale.

A bit of good news is that while all parts of Oleanders are poisonous, it does not affect the soil it’s growing in or the plants around it.

Surprisingly, there are quite a few garden plants that are considered poisonous. For more information on these plants, or parts of plants, take a few minutes to check out Poisonous Plants, a University of California Agriculture and Natural Resources publication:                            https://anrcatalog.ucanr.edu/pdf/8560.pdf 

If someone has ingested Oleander leaves or flowers and is exhibiting adverse symptoms, contact National Poison Control Center at 1-800-222-1222. Remember to be very careful around Oleanders. Better safe than sorry!

Master Gardener classes are offered monthly throughout the county. You can find our class schedule at: http://mgeldorado.ucanr.edu/Public_Education_Classes/?calendar=yes&g=56698, and recorded classes on many gardening topics here: http://mgeldorado.ucanr.edu/Public_Education/Classes/ and specific class recording on fire resiliency here: https://mgeldorado.ucanr.edu/Public_Education/Classes/Landscaping_Class_Presentations/

The Sherwood Demonstration Garden is open weekly on Friday and Saturday from 9 a.m. -noon until March through October. We do close in case of rain, please check our website for details https://ucanr.edu/sites/EDC_Master_Gardeners/Demonstration_Garden/

Have a gardening question? Master Gardeners are working hard to answer your questions. Use the “Ask a Master Gardener” option on our website: mgeldorado.ucanr.edu. or leave a message on our office telephone: 530-621-5512. We’ll get back to you! Master Gardeners are also on Facebook, Instagram, and Pinterest.

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