Growing Sweet Potatoes
Hi- all of the major cultivars available through online suppliers of sweet potato slips will grow well in MD. Among those are Jewell, Georgia Jet, Vardaman, Bush Porto Rico, Centennial, and Japanese Red.
Plants are sometimes available locally at farm/garden stores. You can find a number of online businesses that specialize in sweet potato slips. Many online seed companies also carry them. If you buy them online and they reach you by mail you may be surprised to see some slimy, rotting foliage. As long as the roots are healthy they usually do fine once planted. You can also pot the plants up into containers to hold them until you are ready to plant.