cashs_mom, you can dry the veggies in the oven at a very low temp such as 250 or lower if yours goes that low. I also dry zuccini and mushrooms as I found a recipe in a doctor's office a couple years ago for a beef/mushrrom barley soup and it called for dried mushrooms. That's when I decided to try drying mushrooms. The zucchini I'll put thru the food processor until not quite a powder as this way I don't have to grate them. I also leave the skin on them too.
My squash soup I do the same with adding all sorts of veggies into it before I puree it and then add the chopped up sausage. You may see a bit of carrot or red pepper occasionally but that's just all the fun in it.