Toxic plants in the garden — what to watch for with children and pets

Many classic garden plants — from a yew hedge to an ornamental azalea — contain toxic compounds to varying degrees. That’s not a reason to give up growing them, but it’s worth knowing what’s in your garden, especially where young children play, or dogs and cats that happily try nibbling on anything. In the Atlas-Flora database, every plant card has a toxicity section rating the severity (none/mild/moderate/high/fatal) separately for people, dogs, cats, horses and rabbits.

Highly toxic plants — exercise particular caution

• Common yew — one of the most toxic garden plants there is. Its needles, bark, wood and seeds contain heart-affecting taxine alkaloids; fatal to people, dogs, cats and horses. Only the red aril around the seed is safe to eat — the seed itself inside it remains toxic. It’s a common hedging and topiary plant, so it’s worth knowing if one is growing nearby.
• Candle larkspur — the whole plant, especially young leaves and seeds, contains highly toxic diterpenoid alkaloids; fatal to people, dogs and cats, and highly toxic to horses and rabbits.
• Horse chestnut — raw conkers, bark and leaves contain saponins. Moderately toxic to people and dogs, but — despite the name — highly toxic to horses, for which raw conkers and shoots should never be fed.

Popular ornamentals with toxic parts

• Japanese azalea and rhododendron — the entire plant contains grayanotoxins, which cause heart rhythm disturbances if eaten; highly toxic to people, dogs, cats and horses. The same mechanism is behind the historical “mad honey” made from the nectar of some Rhododendron species.
• Elderberry — an important distinction: raw, unripe berries, along with the bark, leaves, roots and seeds, contain cyanogenic glycosides (moderate toxicity), but ripe, cooked berries (e.g. made into syrup) are safe and traditionally eaten. The problem only arises from eating them raw or unripe.

How to make a garden safer with children or pets around

1. Get to know the plants in your garden. Check each card in the database — the “Toxicity” section shows the real level of risk to people, dogs, cats, horses and rabbits separately.
2. Plant highly toxic species out of reach of young children and pets, or skip them altogether if the risk concerns you.
3. Teach children a simple rule: no berries, seeds or leaves from the garden without asking an adult first — even if they look edible.
4. When working with yew or other highly toxic plants, wear gloves and avoid getting the sap on your eyes or open wounds.
5. If something is eaten, act right away — see the FAQ below.

Check every plant before you buy it

Before planting a new species, especially with young children, a dog or a cat at home, check its card in the plant catalogue and read the toxicity section — it takes a few seconds and can save you serious worry later.