I love vines, especially edible ones.
Leaves of the Ipomoea batatas are tender and sweet when young, but they do turn bitter if allowed to get much bigger than these. The good news is that this vine will not only keep producing tender young edible leaves indefinitely, but pinching them back will make the plant spread out and become more attractive as well as more edible. The edible leaves, moreover, are a rich source of lutein, as well as Riboflavin and Vitamins A and C.
Ipomoea plants are easily propagated by stem cuttings.
Extra nitrogen will encourage more leaves and discourage the formation of tuberous roots. Red lines and/or yellowing leaves indicate nitrogen deficiency, unless you are dirt gardening and have tubers below the ground. Then, of course, the yellowing leaves indicate they are ready for harvest.
As with cucumbers, long hours of daylight interfere with the production of flowers. That is one reason we seldom see sweet potatoes blossoming.
