Health officials in Canada's retirement haven of Victoria, British Columbia, are warning senior gardeners dirt can be deadly, as three deaths last year show.

Chief Medical Health Officer Richard Stanwick said three people over the age of 50 died of tetanus on Vancouver Island last year, and it's likely they acquired it from soil in their gardens, the Victoria Times Colonist reported.

"They were all people who haven't had a (tetanus) immunization in at least 10 years or longer," he said. "There's a lot of risk in the garden."

Tetanus, also known as lockjaw, is an infection found in manure and soil that thrives on damaged tissue, and makes its way into the body through even the tiniest of cuts, he said.