Something that I've heard quite regularly† is that when you plant your tomatoes, you should put an aspirin under each plant. Apparently salicylic acid both increases the number of blooms and strengthens the plant's immune system.
I've been unable to find any references for studies done on this. Nor have I found it discussed on some of the sites or in books that I find more trustworthy.
So, does anyone know of any good references for this?
Does anyone have an explanation of why aspirin in particular helps tomatoes?