Common garden plants that are poisonous to dogs and cats in South Africa

Nobody plants something dangerous on purpose. It happens because a shrub was already in the garden when you moved in, or because it was the only thing flowering at the nursery that Saturday, or because it looked good in a pot on the stoep and nobody mentioned the berries. Most of the plants on this page are sold in ordinary garden centres across the country, which is exactly why they catch people out.

We are not going to tell you to rip everything out. Plenty of these plants are worth keeping if you can put them somewhere an animal cannot reach. What matters is knowing which ones are serious, what the early signs look like, and what to do in the first hour. If you want the wider picture on setting a garden up safely, our guide to building a pet-friendly garden covers mulch, bait and pot placement.

Cycads and sago palms, the worst of the lot

If we could get one plant out of South African gardens with dogs in them, it would be this one. The ASPCA lists sago palm together with other cycads and zamias as toxic to dogs, cats and horses. The toxic principle is cycasin, and the clinical signs run from vomiting and increased thirst through bruising and clotting problems to liver damage, liver failure and death.

The seeds are the most dangerous part and they are bright orange, hard, and about the size of a dog toy. A cycad in a bed the dog walks past every day is a genuine risk, not a theoretical one. If you love the look and want to keep one, put it in a raised pot on a wall or in a fenced front garden the dog never enters.

Lilies, which are a cat problem more than a dog problem

True lilies of the Lilium genus are in a category of their own where cats are concerned. Pet Poison Helpline is blunt about it: every part of the plant is toxic to cats, including leaf, stem, flower, pollen, vase water and root, and ingestion leads to vomiting, abdominal pain, dehydration and acute kidney failure. Early treatment matters enormously here. The ASPCA lists Lilium species as toxic to cats and non-toxic to dogs, so this is one where the species of pet changes the answer completely.

The part people miss is the vase. A cut arrangement on a kitchen counter, pollen dropping onto the surface, a cat walking through it and then grooming its paws, and you have an exposure without the cat ever eating a leaf. If you have a cat, we would keep true lilies out of the house entirely.

Oleander along the boundary wall

Oleander turns up on old suburban boundaries all over Gauteng because it takes heat, drought and neglect without complaining. The ASPCA lists Nerium oleander as toxic to dogs, cats and horses, with cardiac glycosides as the toxic principle and drooling, abdominal pain, diarrhoea, colic, depression and death among the clinical signs. Cardiac glycosides act on the heart, which is why this one is taken seriously even in small quantities.

Dogs do not usually seek it out, but pruning changes that. A pile of fresh oleander clippings on the lawn is far more interesting to a dog than the intact shrub was. Bag the cuttings and get them out the same day, and never burn them near where anyone is sitting.

Azalea and rhododendron under the trees

Azaleas are the classic shade-bed shrub, planted at exactly the height an inquisitive nose finds first. The ASPCA lists Rhododendron species as toxic to dogs, cats and horses, with grayanotoxin as the toxic principle and vomiting, diarrhoea, weakness and cardiac failure as clinical signs. Azaleas sit in the same genus as rhododendron, so the warning covers both.

A shade bed is easy to replace with something safe. Plectranthus, clivia aside, most ferns and ornamental grasses will fill the same space, and our guide to planting a shade container has options that look good without the risk.

Arum lily, which is everywhere after the rain

Zantedeschia aethiopica, the white arum or pig lily, is indigenous and comes up in every damp ditch on the Highveld after good rain. The ASPCA lists it as toxic to dogs and cats, with insoluble calcium oxalates as the toxic principle. Those crystals cause intense burning of the mouth, tongue and lips, heavy drooling, vomiting and difficulty swallowing.

It is rarely fatal, and it is genuinely horrible for the animal while it lasts. Because the pain is immediate, most dogs stop after one mouthful, which is small mercy but a real one.

Delicious monster, syngonium and the whole arum family indoors

The same calcium oxalate problem runs through the indoor plants everyone owns. The ASPCA lists Monstera deliciosa, the delicious monster or Swiss cheese plant, as toxic to dogs and cats with the same insoluble calcium oxalates and the same burning, drooling and difficulty swallowing. Syngonium podophyllum, the arrowhead vine, appears with an identical profile, adding pain and swelling of the mouth to the list.

These are trailing plants that end up on low shelves and coffee tables, which is the worst possible place for them. Put them high, in a heavy pot that will not come down with the plant, and use a decent indoor potting soil so you are not repotting every year and giving the cat another opportunity. Our houseplant care guide goes through placement in more detail.

Brunfelsia, the yesterday, today and tomorrow shrub

This is the one South African gardeners underestimate, partly because it is so pretty when the flowers fade from purple to lavender to white over three days. The North Carolina Extension Gardener Plant Toolbox is direct about Brunfelsia pauciflora: all parts of the shrub are toxic if ingested, especially the berries, to dogs, cats, horses and humans.

The berries are the problem. They form after flowering, they drop, and a dog that likes picking things up off the lawn will find them. If you have a brunfelsia and a young dog, sweep under it after the flowers finish.

Daffodil bulbs and the bulbs in general

The ASPCA lists Narcissus species as toxic to dogs, cats and horses, with lycorine and other alkaloids as the toxic principle, and notes plainly that the bulbs are the most poisonous part. Signs run from vomiting, salivation and diarrhoea through to convulsions, low blood pressure, tremors and cardiac arrhythmias with large ingestions.

Bulb planting season is the risk window. You dig a hole, you leave the packet on the ground while you fetch the watering can, and the dog helps. Plant bulbs in pots instead of beds where you can, so the whole thing sits at knee height and the dog never sees them go in. It also makes them easier to lift and store once they have finished.

What to do if your animal eats something

Phone your own vet or the nearest after-hours veterinary hospital straight away, before you look anything up. Take a piece of the plant with you, ideally with leaves, stem and any berries or seeds attached, because identification changes the treatment. Do not induce vomiting unless a vet tells you to. With the oxalate plants especially, bringing material back up drags the crystals across the same tissue a second time.

The ASPCA toxic and non-toxic plant list is searchable by common name and is the fastest way to check something before you buy it, and our Plant Library is a good second stop when you want to know what will actually grow in your conditions. Where a plant is worth keeping but not worth having at ground level, a heavy cast pot solves it. Something like a cube pot on a wall or a raised plinth puts the plant somewhere the dog simply cannot get to, and it will not tip. Have a look through our bigger pots if you have a plant that needs lifting out of harm's way.

Frequently asked questions

What is the most poisonous plant for dogs in a South African garden?

Cycads and sago palms. The ASPCA lists them as toxic to dogs, cats and horses, with cycasin causing liver damage, liver failure and death. The seeds are the most dangerous part.

Is the delicious monster poisonous to cats?

Yes. The ASPCA lists Monstera deliciosa as toxic to dogs and cats. The insoluble calcium oxalates cause burning of the mouth and lips, drooling, vomiting and difficulty swallowing.

Are arum lilies poisonous to dogs?

Zantedeschia aethiopica is listed by the ASPCA as toxic to dogs and cats. It contains insoluble calcium oxalates that cause intense oral irritation, drooling and vomiting.

Is yesterday, today and tomorrow toxic to pets?

Yes. North Carolina Extension states that all parts of Brunfelsia pauciflora are toxic to dogs, cats, horses and humans if ingested, with the berries being the worst part.

What should I do first if my dog eats a poisonous plant?

Phone a vet immediately and take a sample of the plant with you. Do not make the animal vomit unless a vet instructs you to, because with some plants that causes further damage.