Beware smelly snow mould as your lawn thaws

Noticing smelly, web-like growths on your newly revealed grass during the spring thaw? 

You're seeing snow mould, a fungus that develops when the weather warms up quickly after a cold spell, says Kath Smyth with the Calgary Horticultural Society.

All that freezing and melting creates a pocket of warm moist air between the lawn and the crust of snow above, which is perfect for growing mould, she explains.

"It creates a little greenhouse in between the snow and the ground."

"[Snow mould] really and truly is annoying...it appears where the snow stays the longest and it appears where the soil is packed hard," said Smyth on the Calgary Eyeopener.

It really and truly is annoying."- Kath Smyth

This is usually where people (or pets) have trod on the soil a lot — a pathway, for example. 

Snow mould can be pink or white depending on the type of lawn, and has a pungent odour, she says.

Smyth describes the smell as, "disgusting ... it's a cross between running shoes and, sort of, an outhouse."

It can also be a trigger for allergies, like any fungus or mould.

Despite its foul smell, Smyth describes the threat to your lawn as pretty minor.

• LISTEN to Kath Smyth break down snow mould:

It can kill the grass it grows on, but she says "the trick is to discourage walking on the area for the first little while while it clears itself up."

If you can't wait the problem out until it clears up on its own, Smyth says you can simply wear gloves and rake it up then toss it in a bin.

She advises washing the rake after doing so. She says you could sweep or even mow it up, but sometimes the fungus can stay on your tools and continue to grow.

In a winter where there has been a lot of snow, like last year, she says snow mould typically makes a bigger appearance.

She says you can manage its growth ahead of the spring season by raking up leaves on the lawn in the fall.