The weather has finally warmed up and gardeners across Newfoundland and Labrador have returned to their flower beds.

But once again, many of these happy horticulturists will have no idea they're dealing with poisonous plants.

Monkshood is so common it's considered a heritage plant; But ingesting its foul-tasting flowers can kill you. Munching the pea-like Laburnum seeds, sometimes called golden chain tree, can make you vomit. Contact with Cow Parsnip makes your skin burn.

Beware the tomato, potato, even the innocent-looking buttercup. It's a jungle out there.

"Plants are not poisonous to get us," Anne Madden, education coordinator for Memorial University's Botanical Garden, told the St. John's Morning Show.

"Plants are poisonous to protect themselves. They can't run away from predators."

A common sight

Anne Madden, education coordinator for Memorial University's Botanical Garden, says Bleeding Heart is one of the poisonous plants that's growing in Newfoundland and Labrador. (CBC)

Off the top of her head, Madden can list 27 poisonous plants you'll find in gardens — or growing wild — in Newfoundland and Labrador. And there are probably more.

But her key message is simple: relax.

"Throw a rock and you'll hit a poisonous plant," she said.

"We've lived with poisonous plants for generations. And generally with a little bit of knowledge and a little bit of caution we should all be fine."

Some poisonous plants are so common that most people don't even notice them.

Madden says the bleeding heart is a good example: contact with leaves and roots can cause skin irritation, and consuming large amounts can lead to convulsions.

"I think this is one of the ten most common garden plants in Newfoundland," she said. "The good news is I don't think many people don't have the urge to eat bleeding heart. Or roll in it."

Bleeding Heart, like most toxic plants, contains alkaloids. So does Monkshood.

Need for caution

Monkshood is so common it's considered a heritage plant; But ingesting its foul-tasting flowers can kill you. (CBC)

In 2004, a young man in Newfoundland and Labrador died when he mistook Monkshood for an edible herb.

After the shocking incident, staff at the Botanical Garden were flooded with calls; Madden said people were panicking.

"Monkshood is a plant that Newfoundlanders have been growing from day one. Now they're cutting it out of their gardens... bagging it and asking if they should mark it as poisonous," she said.

Her advice then was the same as now: Monkshood is dangerous if you eat it. But it is perfectly safe if left alone in your garden.

"You should be careful. You should be wary," she said. "I don't put anything in my mouth unless I buy it from the grocery store, the farmer's market, or it's something like blueberries, which I'm very familiar with."

Madden says there are at least 27 different varieties of poisonous plants growing in Newfoundland and Labrador, including the Rhododendron. (CBC)

Pets and children don't always follow that advice. If you have dogs, try chicken wire to keep them out of flowers and vegetable beds, says Madden.

She adds may take more than that simple barrier to protect young children.

"With my daughter (we) grew peas and things in pots on the deck. Separate from the flower gardens so she didn't make the connection that you eat everything."

It's a connection that can be confusing for kids, especially when the roots and leaves of familiar vegetables like tomatoes and potatoes can make you ill.

"My rule is assume it's poisonous," said Madden. "Sometimes most of a plant can be edible — but some parts of it can be poisonous."

Anne Madden's Quick List of Poisonous Plants