The term “potato vine” is frequently used to describe two very different groups of plants, creating confusion for gardeners. It can refer to the aerial foliage of the common edible potato, grown for its underground tubers. It also commonly describes various ornamental species cultivated for their attractive, vining foliage in gardens and containers. This article clarifies these distinctions, focusing on the plant’s structure, decorative uses, and important safety considerations.
The True Potato Plant’s Vine
The true potato plant, Solanum tuberosum, is an herbaceous perennial typically grown as an annual for its starchy harvest. The “vine” refers to the above-ground stem and compound leaves responsible for photosynthesis. This aerial part develops from the underground seed piece, growing up to three feet tall with branching stems.
The leaves are dark green and pinnately compound. The vine’s main function is to generate energy, which is transported down to underground stems (stolons) where the edible tubers form. The vine is rarely grown for decorative appeal and is usually allowed to die back naturally before harvest.
Common Ornamental Potato Vines
The plants most often sold as “potato vines” fall into two primary categories. The Sweet Potato Vine, Ipomoea batatas, is the most common ornamental variety, belonging to the morning glory family (Convolvulaceae). This tender perennial is widely grown as an annual, valued for its fast-growing, cascading habit.
Sweet Potato Vine cultivars boast striking foliage in colors like chartreuse, deep burgundy, and nearly black, often shaped like hearts or deeply cut structures. The other ornamental type is the true ornamental Potato Vine, Solanum jasminoides, which belongs to the nightshade family (Solanaceae). This variety is a true climbing plant, often displaying clusters of small, white or pale lavender, trumpet-shaped flowers. Ipomoea varieties are favored in containers as a “spiller,” while Solanum jasminoides is better suited for training onto a trellis or arbor.
Identifying Toxic Components
Safety is a concern, especially with plants in the Solanum genus (the nightshade family). The true potato plant, Solanum tuberosum, produces toxic compounds called glycoalkaloids as a natural defense mechanism. All green parts of the edible potato plant—the leaves, stems, sprouts, and any green-tinged skin on the tuber—contain these toxins.
The small, round, green fruits that sometimes appear after flowering are also toxic. In contrast, the Sweet Potato Vine (Ipomoea batatas) is generally considered non-toxic in its foliage and tubers, though the seeds can contain a hallucinogenic compound. Gardeners should exercise caution with the ornamental Solanum jasminoides as well, given its close relation to other toxic nightshades.
Growing and Maintaining Potato Vines
Cultivating ornamental vines, particularly the popular Sweet Potato Vine (Ipomoea batatas), is straightforward when providing the right conditions. These plants prefer full sun to partial shade; foliage color is most vibrant with at least six hours of daily sunlight. The soil should be well-draining, rich in organic matter, and kept consistently moist, as the vines are sensitive to drying out.
Ornamental potato vines are considered heavy feeders and respond well to regular fertilization throughout the growing season. Applying a balanced, slow-release fertilizer at planting and supplementing with a liquid feed every two weeks encourages vigorous growth. Since these are tender perennials, they are typically grown as annuals in most regions, with wilting occurring when temperatures drop below 45 degrees Fahrenheit. Regular pruning is often necessary to prevent the fast-growing vines from overtaking neighboring plants.