An annual is a plant that completes its life cycle in one year. A perennial returns year after year from the same root system. There are also plants known as biennials. Biennials take two years to complete their life cycle but there are relatively few of these compared with annuals and perennials. Perennials include iris, daylily, and columbine.
Foxgloves are biennial.
That's a tough question as there are so many perennials that grow great in our area and everyone has their favorites. A. Eggshells should definitely be added to your compost pile as they are rich in calcium. Meat products also take a longer time to break down than vegetable or plant matter. If you wish you can bury meat products deep in the ground but make sure and cover with at least 8 to 12 inches of soil. Some people save all their eggshells, then liquify them in a blender with water to make a calcium rich liquid fertilizer.