Thank you for the question.  There is research based information about using coffee grounds as fertilizer.  From the University of Illinois Extension Educator Jennifer Schultz Nelson:  "Some sources will declare that because coffee grounds contain nitrogen, a major plant nutrient, this makes coffee grounds a great fertilizer. But just because they contain nitrogen, it does not mean that coffee grounds are suitable for use as a fertilizer as is. Some studies have shown that using uncomposted coffee grounds in high concentrations around plants will actually stunt their growth. The grounds need to break down before they are truly a benefit to plants. The grounds need the help of microorganisms in order to release their nitrogen. Research has shown that using coffee grounds in compost piles tends to help the pile reach higher internal temperature. This is an important step in proper composting which helps kill weed seeds and pathogens that may be present in the pile."

"A good rule of thumb for using coffee grounds in the landscape is to either mix them in with existing soil, or in a compost pile mix one part coffee grounds to one part leaves or other dry material plus one part grass clippings or other green material."  Here is the entire publication http://web.extension.illinois.edu/dmp/palette/110109.html 

Here are 2 more publications from the University of Oregan Extension http://extension.oregonstate.edu/gardening/node/1009 

http://extension.oregonstate.edu/lane/sites/default/files/documents/cffee07.pdf

I don't know if anyone has ever tried growing vegetables or tomato plants directly in coffee grounds amended with fertilizer. You could try a few seeds in the mixture to see what happens or try mixing a small amount of grounds with regular seed starter mix.  The research is clear in stating that composted coffee grounds are a great amendment but uncomposted grounds should be composted or worked into the soil to avoid caking at the surface and possible mold growth or stunting of plants.

Thank you for contacting Extension.