Q: I have been reading about the benefits of eating sweet potatoes and I think I would like to grow it here. What do you recommend?
A: The sweet potato, Ipomoea batatas, originated in tropical America and ranked second only to the Irish potato as an important vegetable until World War II. The sweet potato is a good source of sugars, carbohydrates, calcium, iron, and other minerals and vitamins, particularly A and C. The edible part of the sweet potato is a swollen storage root.
The common sweet potato requires a great deal of garden space because it produces long vines. However, there is a cultivar (‘Porto Rico’) which can be more bush or bunch-like and these can be grown in containers. Container grown sweet potatoes will require additional care such as watering and fertilizing but for those of us with limited sunny spaces, bush sweet potatoes are a viable option. Sweet potatoes need warm days and nights so they are considered a warm season vegetable here. The soil pH should be between 5.6 and 6.5, typical of most vegetables. If the soil pH goes near or above 7, the plants will be more prone to diseases.
In Northeast Florida, we recommend planting sweet potato between March and June; it will take about 120 – 140 days to mature for harvesting. Sweet potatoes are grown from slips (transplants) and it is critical for home gardeners to purchase disease-free plants from reputable growers or garden supply stores. Like most vegetables, it is wise to rotate crops and avoid planting the same vegetable in the identical spot repeatedly. If you grow them in containers, then we would suggest you replace the soil each year.
Consider applying ½ your normal fertilizer amounts to the soil 10-14 days prior to planting and mix it well into the soil. The other ½ of the fertilizer can be applied along the sides of the mound (side-dressing) after the plants become established or show evidence of new growth. If you plant the bush variety in containers then incorporate the fertilizer into the top few inches of the soil – do this manually (by hand) to avoid damaging tender roots.
There is another tropical sweet potato, often called the Cuban sweet potato, which can be grown here too. It has white flesh rather than the common orange or yellow flesh we are accustomed to seeing in the grocery stores and in our candied sweet potato recipes during the holidays. Attached is a complete publication from the University of Florida on the Cuban sweet potato: http://edis.ifas.ufl.edu/mv030