A widow whose husband contracted Legionnaire's disease from handling compost said bags should feature stronger warnings about the risk.
Andrew Murphy, from Lanarkshire, was infected by compost he bought to grow his own tomatoes seven years ago.
He died in October from leukaemia. Mr Murphy's wife Margaret said his immune system was left badly weakened after his battle with Legionnaire's, which saw him spend 50 days in intensive care.
Most compost bags instruct gardeners to use gloves and wash their hands after use but Mrs Murphy told BBC Scotland: "We have to have warning labels.
"Nursery school children are using compost to plant sunflowers.
"I would not want another family to have to go through what we've gone through. It doesn't cost a lot of money but nobody's listening. That just upsets me."
Potting compost can harbour Legionella longbeachae, a species of Legionnaires' bacteria.
Scientists believe it is passed to gardeners through breathing in very small dust particles or drops of contaminated water. It cannot be transmitted from person to person.
Five cases of Legionnaire's linked to compost were identified in the Lothians and Tayside in 2013.
Health Protection Scotland say the risk is low but advises gardeners to wear gloves or a mask if working in dusty conditions and to open compost or potting mix bags carefully in well-ventilated areas.
Legionnaire's disease is more commonly caused by the bug Legionella pneumophili, which lives naturally in rivers, lakes and reservoirs, and can be found in man-made structures containing water such as air conditioning systems.
Infections associated with compost are much more common in Australia, New Zealand and Japan, where it accounts for about 30% of all cases of Legionnaires' disease.
The symptoms of Legionella longbeachae include headaches, diarrhoea or a dry cough followed by pneumonia.
Most people recover after treatment with antibiotics but those with underlying medical problems are more vulnerable.