The time had come to dig up some sweet potatoes. We had waited well over 3 months since planting. Our first planting location was around the edge of the banana pit. This is a classic permaculture type of set up. The idea being that the sweet potatoes will help stop invasion of unwanted plants such as grass. From my experience this works well.
That said, I would not use a highly invasive sweet potato in this area again. I have three types of sweet potato growing on property. The first one is a small leaved plant which produces white tubers with a white skin. I have been very pleased with this plant as it is not very invasive; which is what you want when you have a banana pit or don't want the plant to take over.
The second sweet potato is a more of your classic looking plant with medium sized leaves. The plant produces white tubers with a purple skin. This plant almost over took my banana pit. Not to mention about the same space again to the right of the pit (where some grass was).
The third sweet potato is again a classic looking plant. The tubers produced have an orange flesh with the same coloured skin. It has similar rampid tendencies.
As the sweet potato vine had intermingled with the banana, it was a bit challenging to remove the tubers without significantly impacting the banana roots. The main part of the banana pit was compost created at the site, basically heaps of horse manure with grass and a bit of deco. This has turned into a beautiful rich soil. The raised edge around the pit comprised of clay and deco, a rather poor soil (or so I thought).
Upon harvesting the sweet potato from within the banana pit as well as along the edge of the pit (with the so called poor soil), I was extremely surprised to find that the harvest was far greater from the clay/deco mix as opposed to the rich compost. The harvest ratio was about 10 times greater for equivalent space. In the picture, the pile on the left is from a space about the same as the area which the pile takes. The pile on the right is from about 7 times the area of the first pile.
It should be noted that sweet potatoes have significantly better nutritional value than "normal" potatoes. Not only that, for the home gardener, they have the benefit of being able to store the tubers in the soil and harvest when needed. Thus they make a fantastic survival food with a significant enough planting area. Just make sure to harvest the tubers within two years, otherwise the tuber quality can significantly deteriorate.
As for a recipe suggestion, try using them in a pumpkin soup. Basically replace about half the pumpkin quantity with sweet potato. We prefer to roast the pumpkin, sweet potato, onion, and garlic for our soup. Sweet potato is also exceptional eaten baked with half a tsp of fenugreek and some olive oil. Yum! :)