The sweet potato, Ipomoea batatas, is a starchy root vegetable. Unlike the common potato, this tuber is a member of the morning glory family, producing attractive, trailing vines when grown indoors. Starting a vine from a sweet potato is a simple project. This method allows you to sprout the tuber and then propagate the resulting shoots into a long-lasting, tropical houseplant.
Preparing the Sweet Potato for Sprouting
Select a healthy sweet potato, preferably one that has not been treated with sprout inhibitors, which is common with organic varieties. Examine the tuber to identify the “eyes” or small indentations where sprouts will emerge, looking for a specimen that feels firm and has no soft spots. The pointed end should be the one submerged in the water for optimal growth.
To suspend the tuber, insert three or four toothpicks around the middle circumference, spacing them evenly to create a stable tripod. Place the potato in a glass jar or narrow container so that the toothpicks rest on the rim, leaving the bottom third of the potato submerged in water. Place the setup in a warm location, ideally maintaining a temperature around 75°F (24°C), and receiving bright ambient light rather than harsh, direct sun.
Monitoring Slip Growth and Root Development
The submerged portion of the sweet potato will begin to develop fine, threadlike roots within the first week. Simultaneously, small green or reddish shoots, called slips, will begin to emerge from the eyes on the exposed top portion of the tuber.
Maintaining water quality is important for preventing bacterial growth and mold. The water should be changed every two to five days, or whenever it appears cloudy, to keep the environment fresh. Avoiding softened water is also advisable, as its high salt content can inhibit the growth of the developing roots.
The slips are ready to be harvested when they have grown to a length of approximately four to six inches and have developed their own set of small roots at their base. The slips must have their own established root systems before being separated. These individual slips are the actual plants that will be transferred into soil for long-term growth.
Transplanting Slips and Maintaining the Vine
Once the slips have reached the target length and feature a root system of at least one inch, they can be carefully removed from the mother potato. This is done by gently twisting the slip at its base, or by using a clean blade to cut it away. The original sweet potato can remain in the water to continue producing more slips, but the harvested shoots are now ready for planting.
Plant the individual slips in a container using a well-draining potting mix, ideally amended with perlite or sand for aeration. Plant each slip deep enough so that the roots and the lower portion of the stem are covered, leaving only the leaves exposed above the soil line. Immediately after planting, water the soil thoroughly to help the roots settle and eliminate any air pockets.
The sweet potato vine thrives in bright, indirect light, though it can tolerate a few hours of direct morning sun. The plant requires consistently moist soil conditions. Water whenever the top inch of the potting mix feels dry, taking care not to let the container become waterlogged to prevent root rot. Regular pruning of the vine tips is recommended, as this encourages the lateral branching necessary to maintain a dense, bushy shape.