Warmer spring weather has arrived in New Zealand, which means the deadly Legionnaires' disease season has begun.
It is a severe form of pneumonia and is most commonly contracted when dust from compost or potting mix is inhaled.
Now, a new Christchurch-based study out of Otago University is looking at how to make gardening products, like potting mix, safer to use.
One of the supervisors in the study professor Stephen Chambers said while it's "impossible" to make items like potting mix completely safe, he wants to reduce the risks involved from using it.
Testing includes mixing potting mix with water, incubating it for three days, and then testing it for Legionella.
"We're just starting to make some progress, and we're looking forward to seeing if we can do something that's going to be viable for companies to use," Chambers said.
Around 400 people contract the disease each year, one in five end up in intensive care and a quarter of those die.
With people spending more time at home with COVID-19 restrictions, gardeners are urged to be vigilant by wearing gloves, a mask and washing their hands before eating and drinking.
"There's a good chance we'll see a lot of people getting infected unfortunately," Chambers said.
Christchurch resident Nigel Burson, who was struck-down by Legionnaires' disease five years ago, has only just bounced back to full health.
"Putting some compost into a garden and somebody inadvertently threw a shovel full of compost and the northeaster picked it up and I sucked a lung full," he said.
"I would not wish [the disease] on anybody."
He's also calling on gardeners to take special care this spring while in their own backyard.