The winter and spring holidays are prime time to answer this question! There is a story commonly repeated that poinsettias are poisonous – not so – they will, however, make a dog or cat drool excessively. By contrast, eating an Easter Lilly can be fatal, as with many members of the Lilly family. Diffenbachia, asparagus fern, and philodendron are common household decoration plants – they can all make pets vomit as a minimum. So, it’s good to be aware before buying decorative plants if one has pets.
There are also plants that can be poisonous to our larger pets – red maple leaf and yew can be fatal to horses and livestock under the right conditions.
The ASPCA has produced an exhaustive list of any plant that can be fatal, mildly toxic, or annoying, as well as listing safe plants. It is a great resource, but at the same time, just because a plant is on the list, don’t assume it causes fatality – yew is fatal, poinsettia makes our pets drool.