Hi Karen,

Coffee grounds don't have a lot of nutrients "as is", and they are better if composted first. Here's some information: https://s3.wp.wsu.edu/uploads/sites/403/2015/03/coffee-grounds.pdf and https://extension.oregonstate.edu/gardening/techniques/coffee-grounds-composting

But in terms of using them as a fertilizer, they probably wouldn't provide enough nutrients to benefit plants...at least not in a vegetable garden. If you want to use them as a slow release fertilizer around perennials, trees, and shrubs, you can, understanding that it's not going to be a significant source of nutrients.