Bob Randall wrote:
Actually, sweet potato spinach is a distinct variety of sweet
potato. The tuber is white starchy, is small, root like, and looks
inedible. The leaves though taste like and look like the tuber
varieties. What makes this variety standout is that it does very well
here in clay soils as an understory plant below persimmons, or
blackberry muscadine stacks.
Conventional sweet potatoes have trouble with tight soils and
certainly don't produce tubers easily in such conditions. I need to
put them in a foot of good soil. Additionally, conventional ones lose
tuber production if you grow them for leaves.
We got our start from the Chinese Organic Gardening Club here in
Houston. See page 550 in Cornucopia II.
Kathy Evans wrote:
Bob, Thank you for telling me about that variety....does this mean you can
or cannot eat "regular" sweet potato leaves? Thanks, Kathy
Good question.
I checked the book Edible Leaves of the Tropics by Martin, Ruberte &
Meitzner. It seems that the leaves of most sweet potato varieties (Ipomoea
batatas) can be used as spinach. The book, however, is full of warnings and
cautions about leaves of many species of tropical plants. Many contain toxic
substances and anti-nutritive factors and must be cooked to reduce these or
eaten in small quantities.
I am trying to get some sweet potato vines to plant, but I doubt I will
get a good variety like the one mentioned by Bob. The variety that Bob
describes would be better suited to my soil which is quite compacted, and I
would like to use the leaves also. But Ill still try whatever variety I
can get as a ground cover.
Charles.
Here is some of what Martin, Ruberte & Meitzner write:
The sweet potato (Ipomoea batatas) originated in the New World
Distributed as far as New Guinea and New Zealand before the time of
Columbus, the sweet potato was an important crop related to the colonization
and welfare of the islands of the Pacific. Its range has since been extended
so that the species is known throughout both temperate and tropical zones.
Propagated vegetatively, the sweet potato is represented by thousands of
varieties, but is seldom seen in the wild state.
Sweet potato is normally a trailing vine, although climbing forms
resembling typical morning glories are known. Although a perennial, its
succulent nature restricts cultivation to short growing seasons of 3-5
months. Unlike many roots and tubers it begins to store starch at a very
early stage, making early harvests possible. It is one of the most
efficient plants to capture the energy of the sun as calories.
Sweet potatoes are grown principally for their starchy roots. However, the
edible leaves and stem tips are well known. Often considered a poor
peoples food, sweet potato foliage has a rich protein content that helps
fill the nutritional gap left by eating principally the protein-poor tubers.
In West Africa, sweet potato greens are particularly important, and
varieties have been developed that are used only for the leaves. These are
especially rich in calcium.
In laboratory study of their cooking qualities, 44 varieties of sweet
potato were found to differ in their general appearance, flavor, and amount
of bitterness. Many varieties have a resinous flavor that is not
objectionable unless quite strong. Because of anthocyanin content and other
phenolics, the cooking water is often unpleasantly colored. It should
always be discarded. Raw leaves are said to contain some HCN, and therefore
thorough cooking is desirable. ..
Because it is so easy to culture, and because the species yields edible
roots as well as leaves, sweet potato merits a place in the tropical garden.
Leaves and tubers can be produced year-round, and plants resist climatic
extremes. Most soils are suitable, but richness of organic material or
nitrogen promotes lush growth of leaves.