I am starting to plan my garden for this summer, and I already have many vegtable seeds to plant wa hoo !

Last year at the end of the summer I had something eatting my zucchini's and the plants and also my watermelons. I could never figure out how they were getting in my garden and it bothers me cause I have it so nothing can get under the fence but those animals are smarter then me i guess. Is there anything I can do so that i wont get those pests. Any certain flowers I can put around the outside of my plant or anything special you do to not get them. Thanks