At a young age of around 5/6, I was in the garden watching my mom prune our very large Elephant’s Ear- she was hacking away at it and these huge discarded leaves had white crunchy looking stems. I’m not sure why she said it, but she did. “Don’t eat those leaves”. Perhaps her telling me not to, is what got the idea in my head in the first place. I took a big bite out of the white crispy bottom stem. I thought it looked like lettuce. Next moment my mouth was foaming and I was crying and my mom was washing my mouth out with soap.

Needless to say, I know FIRST HAND that plants can be toxic. Now as grown adults we have better sense (I hope) and don’t go walking around taking bites out of our indoor plants. However, pets and kids are less inclined to stick to these rules. And so as a plant lovers, it’s something we need to address.

Definitions Matter

The word ‘toxic’ is a hugely loaded term and can put any pet owner or parent off ever having a plant in their house again.

However the levels of toxicity are very wide ranging. They can vary from mild irritation and in VERY severe cases organ failure resulting in death. These levels of toxicity also differ not only from species to species but also because of varying environmental factors such as the parts ingested or the vegetative stage (Bertero, Fossati, Caloni, 2020).

The issue with the internet is that most sources just list plants as ‘toxic’ or ‘non-toxic’, they don’t go into detail about how toxic specific plants are (and indeed, there isn’t much research on this). I think it often results in websites erring on the side of being extra precautious and listing something as toxic without explaining what precisely that means because they’d rather not be at the end of a law suite. Now if you have a pet or a kid that you’re worried about, then perhaps it is the best to err on the side of caution. You’ll find the Araceae family (including genera such as Anthurium, Arum, Caladium, Monstera, Philodendron and Pothos) as the most demonised plants as they are all flat-out labelled as toxic.

But I’m not a fan of the way half-baked information is used to put the living fear into people. So let’s look at some practical information regarding the term by adding in another layer – ‘mildly toxic’.

Mildly toxic plants might be labelled as ‘toxic’ but it actually takes a VERY large consumption to do any harm. Some of these mildly toxic plants include Pothos, Philodendrons, ZZ plants, Sansevierias, Monsteras, Dracaenas, and Ficus trees.

This doesn’t mean you should take the toxicity of plants lightly, there are definitely some plants that are known to be very dangerous when consumed. Around 6-11 % of pet poisoning enquiries made to vets in Europe are due to plants (Bertero, Fossati, Caloni, 2020). Examples of truly toxic plants include Euphorbia, Dieffenbachia, Lilium, and Sago Palms.

Why toxic?

What makes some of these plants toxic? Well, most sources say it’s because these plants have a high content of calcium oxalate crystals. However, did you know that there are many plants that we eat that have these crystals presents such as Spinach, Brussels and Lettuce. Oxalate has in fact been recognised as one of the reasons for kidney-stones in people (SK Norton, 2017). So it’s not necessarily the fact that a plant has these crystals at all that make it helluva dangerous, in fact there are lots of other things going on that science is still honing in on.

Tl;dr We suspect it is calcium oxalate crystals but we’re not actually sure.

Know your plant

If you are a pet owner or if you have young children, know what plant species you have as it is this information that can help a medical professional rapidly intervene on the target organ of the toxin. In one study, 87% of cats that received prompt care based on their diagnosis developed only mild signs without consequences (Bertero, Fossati, Caloni, 2020). And when I say know your plant, I’m talking about the scientific name, even if you have to jot these down in a journal somewhere. There are many types of lilies that could do varying damage to animals. Some plants are called lilies and aren’t actually part of that family, so knowing the specific name could literally help save a life.

Know your charge

Whether it be that you are living with a pet or a child, there are certain instances that fluctuate the risk of having ‘toxic’ plants in your house.

I have 3 cats, a dog and a toddler in my house as well as over 300 odd toxic plants. Why do I take this risk? Because I know my animals and my child. All my charges grew up around plants from the get go, so indoor plants are not novel to them. My cats are outdoor animals that have plenty of stimulation and healthy vegetation to graze on. This lack of interest in plants coupled with accessible stimulation and vegetation has resulted in me having pets who don’t give a damn whether I place a Begonia or an Anthurium next to me. That makes me lucky to a degree.

Not everyone under your roof is guaranteed to have this environment or personality. Generally the younger an animal, the more likely they are going to be curious about a new plant and might even like the idea of taking a bite out of it. Bored animals and/or animals who don’t get to go outside might do the same.

Being Safe

If you know your animal or child is bound to take a bite out of a toxic plant then make sure they can’t reach them. High shelves and plant stools can help with this.

However cats are notorious for getting places where they don’t belong, so if you have a Edmund Hillary that climbs up walls AND nibbles on plants, then it’s best to be more cautious. Another way one can keep ornamental plants away from animals and children is by putting them in a terrarium or glass casing. There are also other anecdotes available on the web such as sprinkling cayenne pepper on your plants to deter animals or not using kelp fertiliser as this entices dogs to eat around the plant.

If none of this is possible and you do have charges under your care who might take a bite, then it is best to not keep highly toxic plants under the same roof. There are many wonderful plants that are not toxic that you can start exploring. Begonia, Peperomia, Prayer Plants and some Ferns to name a few.