The sweet potato vine (Ipomoea batatas foliage) is a vigorous, sprawling component of the plant, often overlooked in favor of the underground tubers. This fast-growing perennial produces a large volume of biomass throughout the season, prompting gardeners to manage the excess growth. Although the primary harvest is the storage root, the dense vines are a resource that can be reused or recycled rather than discarded. The foliage offers various practical uses that maximize the value of the entire crop.
Using the Vines as Edible Greens
The leaves and young stems of the sweet potato plant are a highly nutritious and widely consumed green vegetable globally. The tender, new growth, particularly the vine tips and young leaves, offers the best texture and flavor for culinary use. These greens are rich in micronutrients, containing higher concentrations of protein, dietary fiber, and vitamins than the tuber itself. They provide substantial levels of Vitamin A (as beta-carotene), Vitamin C, B vitamins like B6, and minerals such as iron and calcium.
Preparation methods are important for maximizing the nutritional benefits and palatability of the greens. The foliage contains moderate levels of oxalic acid, which can interfere with mineral absorption. Cooking techniques like boiling or steaming are effective for reducing the oxalate content. Discarding the cooking water after a brief blanching or boiling session significantly lowers the levels of these compounds.
Once cooked, the greens have a mild, slightly sweet flavor and a texture comparable to spinach. They hold up well in various cooked applications, including stir-fries, stews, and soups. Adding a small amount of fat, such as olive oil, during cooking helps the body better absorb the fat-soluble Vitamin A present in the leaves. The leaves can be harvested continuously throughout the growing season.
Starting New Sweet Potato Slips
The vines can be used for vegetative propagation, offering a simple way to create new plants and expand the crop. A “slip” is a rooted cutting, and sections of the vine can be used to generate these new plants. To begin propagation, select healthy, 6 to 12-inch sections of vine. Make a clean cut just below a leaf node, as this is where roots naturally form.
Remove the leaves from the lower two-thirds of the cutting to prevent rotting once submerged. The vine cuttings can then be placed in a container of water, ensuring the nodes are fully submerged, or planted directly into moist, well-draining soil. Roots should emerge from the nodes within a week or two, indicating the cutting is ready for planting. Propagating slips from the vines is an efficient way to use pruned material and ensure a continuous supply of plants.
Composting and Soil Incorporation
When the growing season ends or substantial pruning is necessary, the volume of sweet potato vines requires thoughtful disposal to return stored nutrients to the soil. The vines are a high-nitrogen or “green” material. They break down quickly in a compost pile when mixed with sufficient “brown” material, such as dried leaves or shredded paper. Proper management is necessary because the vines can re-root and sprout if they are tossed in whole.
To prevent unwanted growth, the vines should be chopped into small pieces, ideally two inches or less, before being added to the compost heap. This disrupts the plant’s ability to sprout from the nodes and accelerates the decomposition process. The resulting compost is rich in organic matter, which significantly improves soil structure and water retention.
Alternatively, the vines can be used as green manure by chopping the foliage and immediately turning it into the soil at the end of the season. This method incorporates the biomass directly, enriching the ground with nitrogen and carbon as it decomposes. The vines can also be laid on garden beds as a surface mulch, but this requires drying or thorough chopping to prevent the material from rooting and becoming a weed.
The foliage also serves as a palatable and nutritious feed for livestock, including cattle, goats, pigs, and rabbits. It offers a high-protein supplement to their diet. The crude protein content in the leaves can be high, sometimes ranging from 18 to 33% of the dry matter, making them a valuable source of forage. Recycling the vines as animal fodder is a method of nutrient redistribution, as the material is consumed and returned to the soil as manure.