Toxic shocker: The Northumberland garden with killers in its midst

It's the week leading up to Halloween, so how timely that Timber Press should send me a copy of Wicked Plants, the A-Z of Plants that Kill, Maim, Intoxicate and Otherwise Offend (£9.99). The creepy title and cover design give it the air of a Lemony Snicket, but while it's the perfect gift for anyone considering Snicket-esque murder, it's actually by the Californian gardener Amy Stewart.

Poison gardens have become rather fashionable. One has been proposed for next year's Chelsea, and more permanently, there's the famous one at Alnwick, created in 2004 by the new Duchess of Northumberland. The duchess even has cannabis growing in a cage – which is more than can be said for the Oxford Botanic Garden, where last summer it was growing, neatly labelled but, gasp, uncaged.

Poisonous and intoxicating plants fascinate us, but knowing your poison is a necessary skill. Especially those with kids. A baby can have a handful of green growth whipped off a bush and into its mouth at Olympic speed. Which generally leaves you wondering just how bad a taste of honeysuckle might be for the tiny pruner.

The really dangerous plants in your garden can be surprising. Wisteria is wickedly toxic. And the autumn crocus, colchicum, is one of the most toxic plants grown widely in gardens. Its pretty pink blooms are gorgeous in the cold days of October, but the leaves have resulted in death from kidney and liver failure.

Other favourites, while less dangerous, will still send you to A&E. A friend of mine (with less than perfect eyesight) spent several hours in casualty after a brush with what she thought was garlic, but turned out to be some daffodil bulbs. Praised by Wordsworth for its aesthetic qualities, the humble daff will leave you with intense stomach cramps and vomiting – which is one major incentive to avoid planting it in any soil you also use for veg.

Although berries as a rule are best avoided, some are not just edible, but palatable. When I joined the Fuchsia Society a couple of years ago, I was immediately furnished with a rather delicious recipe for the odd little glacé cherry-like fruits that appear after their gaudy flowers. And Pam Corbin's River Cottage Handbook Number 2, "Preserves" (Bloomsbury), contains a good one for hedgerow jelly that would use up most of the berries in my road, where the trees are rowans, crab apples and hawthorns. So try to stay calm: though a heart attack looms at the moment you see your child with a mouthful of berries, a proper identification is always your best bet.

People with small children and pets should avoid planting anything on the RHS's poisonous plants list (rhs.org.uk)

What's your poison?

Datura

According to the Duchess of Northumberland, in South America the flower is used on a baby's pillow for a few minutes to lull the nippers to sleep. Nevertheless: deeply toxic, highly hallucinogenic, and liable to prevent you remembering to breathe

Oleander

Many of the most dangerous plants kill by containing cardiac glycosides, which regulate your heart – and Oleander is one of them. A popular street plant in the Med and terrace plant in the UK, it killed toddlers as recently as 2000

Elderberry

Happily edible once cooked, the raw version caused a mass hospital evacuation in the US during the early 1980s. Most parts of the plant have high cyanide content, and shouldn't be eaten