Today, Monday, April 6, is sweet potato day. I find this odd because here in Virginia, one does not plant or harvest sweet potatoes at this time. So I did some digging (no pun intended) and discovered the origins of the date.
In Benton, Kentucky, there is an annual sweet potato event the first weekend in April. Apparently, the sweet potato grows well in Kentucky’s hot, humid summers and was very popular in the 1800s as an easy cash crop. Tater Days is celebrated with a parade, a carnival, and baking and canning contests. Put that on your bucket list for 2021.
Sweet potatoes are botanically different from white potatoes. Sweet potatoes (Ipomoea batatas) are in the morning glory family while white potatoes (Solanum tuberosum) are in the nightshade family. Both produce tubers but sweet potatoes are planted in the summer and harvested in the fall, while white potatoes are planted in the early spring and harvested in the summer. Sweet potatoes need a long growing season, at least 4 months, and thrive in our hot and humid summers, much like Kentucky.
While white potato plants are started with chunks of the tuber, sweet potatoes are grown from rooted sprouts called slips. Slips may look like limp, short stems with no roots. If you order slips, plant them when the soil has warmed to at least 60 degrees and nighttime temperatures are above 60 degrees. If it is too cold, pot them up and hold them inside near a sunny window.
Plant slips about a foot part, covering with soil up until the first pair of leaves. These plants are usually grown in the ground, in loose, well-drained soil. These plants are vines that grow several feet long so give them plenty of space. The green, heart-shaped leaves are edible (deer like them too). The plants will grow up until frost and the tubers should be harvested before the first heavy frost. Southern Exposure Seed Exchange sells slips but try any company that specializes in vegetables.
Then there are ornamental sweet potato plants grown for beautiful foliage in a wide range of colors. Ornamental sweet potato plants can have chartreuse, dark purple, bronze-red, mahogany red, or variegated cream, green, and red colored leaves. These are used frequently in containers in Washington DC’s public spaces and gardens because the vines are ideal “trailers,” draping over containers. Since they are tropical plants, they tolerate DC’s heat and add quite a lot of color. Proven Winners sells many different types as small annuals in cell packs at local independent garden centers.
However, in this topsy-turvy world now, there is a new line of sweet potato plants that have beautiful ornamental foliage (still edible) and produce tubers for harvest. Treasure Island Sweet Potatoes, represented in this country by Concept Plants, have been bred by Louisiana State University AgCenter from an original concept development and collaboration work by their partner FitzGerald Nurseries in Ireland. These plants can be grown in a container in the summer for colorful leaves and the tubers can be harvested in the fall. The plants in the Treasure Island series are named after different Polynesian Islands because each plant “hides” a treasure underneath the soil.
There are five plants:
Tahiti with green leaves and purple tubers
Tatakoto with dark green purple leaves and orange tubers
Makatea with golden green foliage and white tubers
Kaukura with purple foliage and orange tubers
Manihi with dark purple foliage and orange tubers.
These new plants would make an ideal children’s gardening project and vegetable container plant for those with limited space. Several of the Treasure Island series can be ordered from Spring Hill Nursery. Images courtesy of Spring Hill Nursery and Concept Plants.