The ornamental sweet potato vine (Ipomoea batatas) is a herbaceous plant widely cultivated both for its aesthetic qualities and its nutritional value. Belonging to the Convolvulaceae family, it stands out for its versatility in landscaping, as well as being an important food source in various cultures. Both the sweet potato selected for food use and the ornamental sweet potato belong to the same species, but have been selected for different purposes.
The genus name, Ipomoea, derives from the ancient Greek “ἴψ” (ips), meaning ‘worm’ or ‘caterpillar’, and “ὅμοιος” (hómoios), meaning ‘similar’. This name refers to the climbing and twining growth habit of the plants in this genus, which resembles the sinuous movement of worms. The specific epithet, “batatas“, is an adaptation of the indigenous term “potato” or “potatoes”, used by natives of the tropical regions of the Americas to designate this plant.
Originally from the tropical regions of the Americas, especially what is today Ecuador, the sweet potato was domesticated at least 5,000 years ago. Archaeological evidence indicates its presence in Central America during this period, suggesting that its domestication occurred between the Yucatán Peninsula in Mexico and the mouth of the Orinoco River in Venezuela.
From these regions, the plant was spread by indigenous peoples to the Caribbean and other parts of South America. Today, the sweet potato is cultivated in various tropical and subtropical regions around the world, adapting to a variety of habitats, from coastal plains to mountainous areas. Its lifecycle is perennial in its regions of origin, but in temperate climates, it is often cultivated as an annual due to its sensitivity to cold.
The sweet potato has significant importance both as food and as an ornamental plant. From a nutritional perspective, its tubers are rich in low glycemic index carbohydrates, fiber, vitamins A and C, and minerals such as iron and potassium, making it an essential source of nutrients in many diets around the world. The leaves and shoots are also consumed in some cultures, adding nutritional value to the plant.
The ornamental sweet potato is a herbaceous vine with tuberous roots that store nutrients. These tubers vary in shape, size, and color depending on the cultivar and are the primary edible part of the plant. The growth habit is either spreading or climbing, with long, slender stems that can reach 3.3 to 9.8 feet (1 to 3 meters) in length. The stems are generally herbaceous but can become slightly woody with age. The leaves are alternate, simple, and vary in shape from heart-shaped to lobed, with palmate forms, displaying a wide range of colors, especially in ornamental varieties.
Sweet Potato vine flowering typically occurs from late summer to early autumn, although in many ornamental cultivars, flower production is lesser. The inflorescences are cymose, with flowers either solitary or grouped in small clusters. The flowers are hermaphroditic, with a funnel-shaped corolla typical of the Convolvulaceae family and quite similar to those of Morning Glory (Ipomoea purpurea), ranging in color from pale pink to violet. Pollination is usually carried out by insects, particularly bees, attracted by the nectar of the flowers. After pollination, capsule-type fruits that contain dark seeds are formed.
Sweet Potato plays a prominent role in various culinary traditions, particularly in Latin America, Africa, and Asia, where it is used in both sweet and savory dishes. As an ornamental plant, cultivars have been developed with an emphasis on leaf aesthetics, presenting leaves in varied colors such as purple, lime green, and bronze, and different shapes, from the most intricate to heart-shaped. These varieties are widely used in landscaping projects, especially in pots and hanging baskets, due to their creeping to trailing growth habit, and are very vigorous.
The main ornamental cultivars are:
- ‘Blackie’: Features deeply lobed leaves in a dark purple, almost black color. Its growth is vigorous, making it ideal for hanging baskets and borders.
- ‘Margarita’ (also known as ‘Marguerite’ or ‘Sulfur’): Noted for its large heart-shaped, bright lime green leaves. It is one of the most vigorous cultivars, excellent for covering large areas quickly.
- ‘Ace of Spades’ (also known as ‘Black Heart’ or ‘Purple Heart’): Features cordate leaves in an intense purple hue, providing a striking contrast in landscape arrangements.
- ‘Tricolor’ (also known as ‘Pink Frost’): Presents variegated leaves in green, white, and pink, adding a vibrant and colorful touch to gardens and containers.
- ‘Sweet Caroline’ Series: This series includes several cultivars developed by North Carolina State University, featuring various colors and leaf shapes:
- ‘Sweet Caroline Green’: Bright green leaves.
- ‘Sweet Caroline Light Green’: Lighter green leaves.
- ‘Sweet Caroline Purple’: Purple leaves.
- ‘Sweet Caroline Red’: Reddish leaves.
- ‘Sweet Caroline Raven’: Black leaves.
- ‘Sweet Caroline Bronze’: Bronze-toned leaves.
- ‘Illusion’ Series: Known for its finely divided leaves and distinct colors:
- ‘Illusion Midnight Lace’: Deeply lobed dark purple leaves.
- ‘Illusion Emerald Lace’: Emerald green leaves, also deeply lobed.
- ‘SolarPower’ Series: This series was developed to offer more compact and controlled growth, suitable for smaller spaces and containers:
- ‘SolarPower Lime’: Lime green leaves.
- ‘SolarPower Red’: Reddish leaves.
- ‘SolarTower’ Series: Stands out for its vertical growth habit, ideal for trellises and vertical structures:
- ‘SolarTower Black’: Dark leaves.
- ‘SolarTower Lime’: Lime green leaves.
- ‘Sweetheart’ Series: Characterized by heart-shaped leaves:
- ‘Sweetheart Light Green’: Light green leaves.
- ‘Sweetheart Red’: Vibrant red leaves.
- ‘Sidekick’ Series: Known for its more contained growth and lobed leaves:
- ‘Sidekick Black’: Dark purple leaves.
- ‘Sidekick Lime’: Lime green leaves.
In landscaping, ornamental Sweet Potato Vine is often used as ground cover, covering the soil with its vigorous growth and forming a dense carpet of colorful foliage. This not only beautifies the environment but also helps in weed control and moisture conservation of the soil.
Moreover, its prostrate growth habit allows it to be used in the edging of flower beds, outlining paths and specific garden areas with its vibrant colors. When grown in pots and hanging baskets, ornamental Sweet Potato displays a cascading effect, with its long vines gracefully hanging over the edges of the containers.
This feature makes it ideal for decorating balconies, terraces, and patios, adding a vertical dimension to the design of the space. The plant can be used to cover trellised structures or in vertical gardens, creating a curtain of lush, colorful foliage. Its ability to grow as a climber allows it to be led along supports, adding height and visual interest to the garden.
The texture of the leaves of ornamental Sweet Potato varies depending on the cultivar, ranging from smooth to deeply lobed, which adds tactile diversity to the landscaping. The colors of the leaves, which range from light to darker shades, allow for harmonious or contrasting combinations with other plant species. For example, the lime-green leaf variety can be combined with plants with purple foliage or warm-colored flowers to create a striking contrast. The dark-leaved cultivars, such as ‘Sweet Caroline Raven’, harmonize well with light-toned flowers, standing out in the arrangement.
Interesting combinations can be made with plants such as coleus, which also offers a variety of colors and leaf patterns, creating a vibrant and dynamic flowerbed. The use of ornamental grasses alongside the ornamental Sweet Potato adds movement and lightness to the ensemble, while plants with abundant flowering, such as petunias and calibrachoas, complement the foliage with their colorful flowers. Moreover, integrating aromatic herbs like thyme and oregano not only enhances the visual aspect but also contributes pleasant aromas to the environment, making the garden beautiful and functional.
The adaptability of the ornamental Sweet Potato to different garden styles is remarkable. In tropical gardens, its lush leaves and intense colors complement the dense and diverse vegetation. In contemporary gardens, dark-leaved cultivars offer a touch of sophistication and modernity.
In country-style gardens, the combination with wildflowers and other rustic-looking plants creates a more welcoming and natural atmosphere. However, what we cannot expect is for it to go unnoticed, especially in cultivars with intense colors.
The ornamental Sweet Potato thrives in environments with high direct sunlight exposure. Although it tolerates partial shade, full sun exposure enhances leaf color and gloss, desirable characteristics in ornamental projects. Therefore, planting in areas that receive direct sunlight for most of the day is recommended. This species adapts to various conditions but performs best in warm and humid climates.
The ideal temperature for its cultivation is between 75°F (24°C) and 79°F (26°C). Although it tolerates temperature variations, it is sensitive to frost and very low temperatures, which can impede its growth and beauty. Proper ventilation is beneficial to the health of the Sweet Potato plant, helping to prevent fungal diseases and ensuring an environment conducive to its growth. However, one should avoid areas with strong and constant winds, which can cause physical damage to leaves and stems.
The ideal soil for ornamental Sweet Potato should be fertile, well-drained, and rich in organic matter. Compacted soils or those with poor drainage can lead to waterlogging, increasing the risk of root rot. It is recommended to incorporate organic compost or worm castings to improve soil structure and fertility.
Regarding watering, it is crucial to keep the soil consistently moist, but not waterlogged. The frequency of watering should be adjusted according to weather conditions and soil type, ensuring adequate water balance. Avoid letting the leaves of your ornamental Sweet Potato vine wilt due to lack of water, which can signify considerable water stress.
Regular fertilization is essential for the vigor and intense coloring of the foliage. The use of organic fertilizers, such as aged manure or worm castings, is prioritized, applied periodically around the plant, avoiding direct contact with the stem. This practice ensures the availability of nutrients necessary for healthy plant development. Furthermore, after the plant’s cycle, you can harvest Sweet Potatoes for consumption, free from chemical fertilizers.
The maintenance of ornamental Sweet Potato involves cultural practices such as removing dry or damaged leaves, contributing to the plant’s aesthetics and health. Although it does not require frequent pruning, controlling its growth may be necessary to maintain the desired shape and prevent the invasion of adjacent areas.
Over time, the plant can lose its beauty and vigor, and drastic pruning, with renewal of the beds, is recommended. If planted in pots or planters, it should be replanted annually, since the Sweet Potatoes can grow considerably and deform, or even break, the containers.
Ornamental Sweet Potato vine can be grown in containers with water, making it a versatile option for interior decoration. In this mode, it is possible to root cuttings in water-filled containers, creating unique and easy-to-maintain ornamental arrangements. Many aquarists grow Sweet Potato this way in their aquariums, helping to control ammonia levels in the water.
Despite its hardiness, Ornamental Sweet Potato is susceptible to some pests and diseases. Common pests include nematodes, aphids, mites, whiteflies, slugs, and snails, which can cause significant damage to the plant. Among the diseases, fungal infections such as sclerotinia, botrytis, rust, and anthracnose stand out, as well as viral infections transmitted by insect vectors. Proper prevention and management, such as regular inspection and biological control, are fundamental to minimize the impacts of these adversities.
Propagation of Ornamental Sweet Potato is predominantly done through stem cuttings. Healthy branch segments, approximately 8 to 10 inches (20 to 25 cm) in length and containing four to six leaves, are cut and planted directly in the soil or rooted in water. During the renewal of the beds, you can also multiply it using the tubers it produces. These methods ensure the maintenance of the cultivar’s characteristics and allow for the rapid acquisition of new plants for ornamental use.
