Wetter than normal summer fuels fungi

Calgary’s wet weather in July led to an abundance of growth on campus this summer.

According to Environment and Climate Change Canada, Calgary recorded 167.5 mm of rain last month. Typically, our city only sees an average of 65.7 mm of rain in July, so 2025 was one for the history books, making it the third wettest on record.

The moisture combined with the warm temperatures made for optimal growing conditions for many species, such as the natural wildflowers near the Charlton Pond and the East Gate lawn. This year many on campus over the summer couldn’t help but notice a variety of mushrooms growing as well. Not just under trees where they typically are, but in the grassy areas, too.

“When we think of mushrooms, we’re talking about fungi,” explains Dr. Mathew Swallow, PhD, an associate professor in the Department of Earth and Environmental Sciences and soil scientist.

Swallow says many varieties of fungi live in the soil as hyphae, which are the branching filaments that make up the mycelium of a fungus.

“If you see them they are very thin, they look like very thin hair-like structures. That is the actual living part of the fungi.”

Swallow emphasizes there are other kinds of fungi that grow in different ways, but many common outdoor mushrooms come about from hyphae, which are multicellular organisms. That’s compared to other fungi which can be single cell, such as yeasts.

“The main role they play is to decompose. They are like organic recyclers,” he explains, adding that they are part of the carbon cycle. “They break down organic matter in the soil and release that back as CO₂ into the atmosphere.”

Some hyphae, he says, form symbiotic relationships with plant and tree roots. “Because the hyphae are so thin they are able to get to places that the plant roots cannot get to. So they act in a partnership where basically, the plants give the fungi energy and the fungi can then find water and nutrients.”

Fungi play an important role in the ecosystem and while they are always there, we don’t always see them. However, thanks to optimal conditions, we’ve been able to see the fruits of those fungi in the form of mushrooms.

“You need moisture and you need warmth for fungi to thrive and be active,” says Swallow, explaining that mushrooms are actually the fruiting body of the hyphae.

“That’s the thing that is releasing the spores that spread out into the wind and spread the mushroom around.”

So with all of the excess moisture and an average daily temperature of 22 degrees Celsius in July, the hyphae have had perfect growing conditions.

Despite being in abundance on campus, don’t rush to harvest anything. Alberta’s Mycological Society has a list of resources related to the different varieties of mushrooms in the province. As a general rule it is only safe to consume mushrooms that have positively been identified as edible. To keep mushrooms away from pets, simply pull them out in one piece and discard them in composting bins.

Anyone curious about identifying mushroom variety can also visit sites like iNaturalist.