When preparing your soil add compost, straw and other amendments down three to six inches into your soil. Fertilize with a fertilizer high in nitrogen every two to four weeks. Use care to avoid piercing the skin with your work tools. Wash, dry and store in a cool, dry place. Both Sweet Potatoes and Yams are highly susceptible to frost and freeze.
Yams require up to a full year of frost free weather and heat.
As a result, they are only grown in tropical and sub-tropical areas.