Africa is host to a huge number of nutritionally dense traditional and ancient crops. These include orphan crops and unusual speciality food-plants for smallholder production.
For the ecologically sensitive, small-scale farming community, Livingstone potato or Tsenza (Coleus esculentus) is a fascinating orphan crop.
It is one of the root crops known as a “potato” of sorts, although it’s actually more closely related to mint!
Wild potato
Also known as wild potato, veld potato, African potato*, Livingstone potato (Eng); veldaartappel, wilde-aartappel (Afr); itapile (Xhosa); mutada (Venda); ujango, ujilo, umbondwe, umhlaza (Zulu), umbondiwe (Ndebele), tsenza is the Shona name for the plant.
The name gives away the edible part of the crop, its cluster of fingerlike roots.
The huge number of common names this plant has underscores how important it must have been to the people who first domesticated and spread the cultivation of this plant.
Virtual extinction
Unfortunately, this is the very poster child of an orphan crop, with its extensive traditional cultivation being replaced by other crops (specifically taro, cassava and sweet potato) to the point of virtual extinction in South Africa.
The situation had become so bad in the early and mid 2000s that reports of the species growing in the wild were considered worthy of scientific publication!
The crop is still considered important in subsistence agriculture in other countries to the North.
Luckily the modern movement towards traditional crops and diverse planting has revived interest in the plant, and one can find it for sale from seed merchants and nurseries in season (early to late spring).
Cultivation of wild potato
Superbly adapted to dry conditions, all African potato needs to grow is deep, fertile soil in full sun and reasonable summer rain, with a bit of weeding.
Small shrub
The plant is a small shrub, about knee height, with thick, semi-succulent leaves.
Sections of root of about 3cm long or so can be planted about 3cm deep in friable soil once the weather has properly warmed up in September in most areas of the country.
The plant is adapted to porcupine predation in the wild and with dozens of “eyes” on tubers, it can reshoot from very small pieces.
It is best to plant the root sections horizontally, to form a small clump. Harvest can take place anytime in winter when the plant is dormant.
Dormancy is easy to see. The plant will turn yellow and drop all its leaves with the onset of cold weather.
If you leave plants in place over winter never water dormant plants, they will rot.
If your climate is very mild, and the above-ground parts of the plant are not frosted off, you can be rewarded with lovely yellow flowers.
Seed saving and sharing
Store tuber sections in dry sand or coir for replanting in spring, or leave a few clumps in the ground for division and replanting in season.
It is important to store the tubers dry but humid. They will rot if kept wet, and desiccate if kept “naked”.
Uses and potential markets for wild potato
This plant has been cited as being extremely nutritious, with a particularly high starch and amino acid content.
Cultivated varieties taste like potato with a slightly minty undertone. They can be peeled and eaten raw, or used in stews, roasted or even in baking.
High starch root crops have uses in gluten free baking. Recipes along these lines are difficult to find ~ perhaps someone inventive can give it a try.
Potential for development of new products
There is always interest in traditional food ingredients at the right restaurants and fresh food markets, but development of new products is entirely possible from such an underutilized crop.
With the right conditions this is a plant that pretty much grows itself. So it does not deserve the neglect that it has suffered in South Africa in the past.
* Not to be confused with the “African potato” touted by former health minister Manto Tshabalala-Msimang as an ingredient in a cure for HIV-Aids, Hypoxis heamerocallidea.
For more information on this, or other orphan crops, please contact Jason Sampson at jason.sampson@up.ac.za
For more articles on vegetables and crops click here.
All photos credit: Richard Hay.