Coleus is one of my favorite ornamental plants (Solenostemon scutellarioides). It functions as an annual in our zone 6b-7 but is a tropical perennial that can come back each year in the right climate. Tennessee is definitely not the right climate! I enjoy planting coleus because of the many varied colors it can bring to the garden. I like the red colors but the foliage can range from yellow to purple to green with all kinds of combinations in between. Generally speaking coleus likes the shade but plant breeders have made some remarkable advances with more sun tolerant coleus plants.
You don't necessarily have to buy new coleus plants each year. I tend to buy a couple six packs but also supplement our coleus plants in other ways. Coleus is a very easy plant to propagate so I take cuttings before the frosts come in the fall to root and bring indoors. It grows very nicely as a houseplant! In the spring I take cuttings from the plants I have indoors and plant the potted ones outdoors to grow outside.
I also allow my coleus plants to flower and eventually produce seed. Most gardeners try to avoid the flowers for a while by pinching back the stem tips to make bushy plants. I'll pinch them back for a while but once they start to flower I let them go so that the coleus produces seed. Then I collect the seed and sow it in the spring. Planting from seed is a very cost effective way to grow your garden - especially when you grow your own seed!
Sometimes they even sow themselves in your garden!
Do you grow coleus in your garden?