This is why mushrooms are springing up on lawns across the city

Mushrooms are popping up on lawns across the province but a fungal expert warns the toadstools aren't safe for salads.

"There are a few that could be or are poisonous and they're hard to tell apart from the ones that aren't," said Heather Addy, a professor who teaches fungal biology at the University of Calgary.

The recent rise in mushrooms has to do with the wet weather so far this summer. Most parts of Alberta received at least 80 mm of precipitation over June.

"But the fungi are always there," Addy said.

The fungal biology professor says fungi are always growing in the soil underneath lawns but when the temperature, light and nutrient conditions are right, a network of threads starts to form mushrooms.

"It's kind of like having a bunch of fruit trees in your yard that you know nothing about until all these apples and plums [grow]," she said.

Fungi sits dormant throughout the winter. It grows slowly when conditions are dry.

Moisture increases the pressure inside the threads, Addy says, allowing fungi to push its way up out of the soil or through asphalt.

"You can think of it like your bike tire when you pump air into the tube inside the tire," she said. "It's when those threads come together to make the mushroom that they can exert that kind of pressure."

Fungi then reproduce by fragmentation, budding or producing spores under mushroom caps.

'Go to the market'

Earlier this week, health officials warned B.C. residents about the death cap mushroom an invasive species that if not deadly, can cause liver and kidney damage if consumed.

The species isn't native to Calgary but Addy says the city does have other poisonous fungi.

"There's very few [wild mushrooms] that are really yummy, there's very few that are poisonous. But in between you've got tens of thousands that are sort of meh, like, why eat them?Go to a market, buy some really yummy ones," she said.

It's nearly impossible to get rid of fungi because of its size, so Addy suggests people pick up or dig up mushrooms and put them in the compost to protect children and pets.

No chemicals are effective in controlling mushroom-producing fungi, according to the City of Calgary website.

Thecity recommends residents destroy rotting stumps, roots and other organic debris or try dethatching a lawn to remove the fungi's food source.

Or residents can simply "learn to love them," Addy said, adding that while some are pathogens, most yard mushrooms break down organic matter.

"They're really important in getting the nutrients that are locked up in that [dead] wood and the plant stuff back into nature so other plants can get them."