Where has he lived?
I am nearly 71 and have lived in Wisconsin since 1964. I can recall several years prior to and during the 1970s, with May frosts. They aren’t *hard*, but they can injure new starts.
We never plant before Memorial Day or the first week of June. Even if it is a warm Spring, we keep the starts potted in a greenhouse or hoop house and have a heating option available.
This year, the May frost was made worse by 2 weeks of rain. Anyone whose starts survived the frost, ended up with early blight. Our garden was too thick to drink, too thin to plow, so I just put everything in 10-gallon pots and gave away about 60 starts to people who had lost theirs to the rain.
We live in south Mississippi. I’ve never lost plants in MAY to frost before.
My dad has lived here his whole life.