Hopefully, you had glazed sweet potatoes, sweet potato casserole or sweet potato pie for Thanksgiving. I contributed the latter from my own homegrown sweet potatoes. I’m pretty sure none of you hand candied yams since yams aren’t produced or sold in East Texas. Yams (Dioscorea alata) are the roots of a tropical vine and not grown commercially in the United States. Yams are native to Asia and aren’t even in the same family as a sweet potato.
The confusion between yams and sweet potatoes began with the African slave trade. The word “yam” is African and was placed on the similar New World sweet potato which was cooked and eaten in the same manner. Sweet potatoes (Ipomoea batatas) however are in the morning glory family and are native to tropical America.
Because of their tropical origins, sweet potatoes require warm temperatures and a fairly long growing season. This naturally makes them uniquely adapted to the hot, humid South. They are started in the garden after all chances of frost and when the nights and soil are warm. They are planted as slips generally from mid-April through the first of June. “Slips” are simply stem cuttings, with or without roots.
If you have access to an existing weevil free sweet potato vine, the cuttings root very easily in water or small pots. I’ve also direct stuck many fresh cuttings in the garden with no roots at all. After watering in at least once, they almost always root. They do need well-drained soil and full sun for maximum production. The historic sweet potato producing areas in East Texas are fairly sandy which makes for easier digging and more shapely potatoes.
Commercially, sweet potatoes are harvested before the end of the growing season, while the tuberous roots are medium-sized and still attractive. If you wait until the end of the growing season and harvest them, many will be quite large and misshaped. These make fine pies and casseroles however. Sweet potatoes need some time with warm temperatures and high humidity to cure after harvesting. Luckily cured sweet potatoes are for sale in every store and market right now.
Most cooks turn sweet potatoes into even sweeter concoctions. My personal preference is just baked like russet potatoes and eaten with butter (or olive oil) and seasoned salt on them alongside other home grown Southern staples like peas and okra. No matter how you eat them, they are healthier for you than Irish potatoes as All-American sweet potatoes are an excellent source of beta carotene and fiber.
Greg Grant is the Smith County horticulturist for the Texas A&M AgriLife Extension Service. He is author of Texas Fruit and Vegetable Gardening, Heirloom Gardening in the South, and The Rose Rustlers. You can read his “Greg’s Ramblings” blog at arborgate.com, read his “In Greg’s Garden” in each issue of Texas Gardener magazine (texasgardener.com), and follow him on Facebook at “Greg Grant Gardens.” More science-based lawn and gardening information from the Texas A&M AgriLife Extension Service can be found at aggieturf.tamu.edu and aggie-horticulture.tamu.edu.