Answer: You're on the right track. Annuals grow, flower, set seed and then die, all in one growing season. Perennials will grow in the same garden spot for 3 or more years. Annuals are great for seasonal pockets of color; pansies for winter color, marigolds for summer color, etc. Perennials are more like the backbone of the flower bed.
Zinnias can wilt and look pathetic immediately after being transplanted, but they generally recover within a week. Sounds as though you planted them in well amended soil and if you water them deeply every 3-4 days, they should pull through.
Home Depot has a wonderful selection of annuals and perennials. Just decide whether the planting site is sunny or shady and choose annuals or perennials that like those conditions best.
Enjoy your flower garden!
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