A promotional mini-"magazine" arrived today from my local garden center. It included a small article on growing herbs and leafy vegetables indoors year round. At the bottom of the page was a picture of some lighting units and fertilizers, but what caught my eye was a bottle of Mycorrhiza. So being curious, and having some Mycorrhiza on hand I did some searching. Informal testing seems to show that plants, including vegetables grow larger and are more disease resistant when Mycorrhiza innoculents are added to their soil.
Now I have do idea if what I have are even the correct species for veggies, but I am going to give it a try.