Syngonium Plants

Syngonium plants (Syngonium podophyllum or Nephthytis triphylla) are popular indoor plants. Also called an arrowhead plant or vine, they grow well indoors and have beautiful variegated foliage. Native in areas ranging from Mexico to Brazil and Bolivia, these plants grow in U.S. Department of Agriculture plant hardiness zones 10 to 12.

Plant Description and Uses

Although these plants grow outdoors in warmer climates, in most parts of the United States, these plants are grown indoors for their tropical evergreen foliage. Plants have groups of greenish-white flowers that develop into brown-black berries. However, the plants rarely flower indoors.

Young plants have egg-shaped leaves with a heart-shaped base. The leaves can measure up to 5.5 inches, advises Missouri Botanical Garden. As the plant matures, the leaves take on an arrow shape; then the leaves grow in a pedate shape, reaching up to 14 inches long, with five to 11 leaflets.

Young plants do well in pots, but the plant is a vine that likes to climb and can grow 3 to 6 feet long. You can train the plants to grow on a trellis or let the vines hang from a hanging basket. Grow it outdoors as an annual or as a perennial in warmer climates. It's a striking addition to borders and container plantings.

Syngonium Types and Varieties

There are many syngonium varieties to choose from, each with different leaf patterns and coloring. 'White Butterfly' is a popular variety that features greenish-white leaves with dark green edges, advises Costa Farms. 'Exotic Allusion' has light green leaves with flushes of creamy white. 'Berry Allusion' also has light green leaves, but this cultivar features tints of cream and pink.

Not all varieties have green leaves. For example, 'Painted Arrow' has creamy green leaves with light green spatters. The 'Holly' variety has striking white leaves with green edges and veins. 'Strawberry Cream' is another striking variety; the new growth on this cultivar is pink.

If you want a smaller plant, consider compact syngonium varieties, such as 'Julia Allusion' and 'Pink Allusion.' Both plants have light green leaves. 'Julia Allusion' has flushes of coppery pink, while 'Pink Allusion' features dark green edges and pink veins.

Syngonium Plant Care

Syngonium plants are low maintenance and easy to care for. Plant them in a commercial soil-based potting mix. They grow in part shade and will do well indoors in a location with indirect, bright sunlight.

Water the plants regularly to keep the soil moist; add water when the soil surface gets dry. You can cut back on water during the fall and winter months. Syngonium plants enjoy humidity, so you may want to place the pot on a tray of wet pebbles or put a humidifier in the room.

The plants don't need fertilizer, but you can feed them with a fertilizer formulated specifically for houseplants in the spring and summer if desired. Follow the package instructions. No pruning is required. To keep the plant growing in a bushier form rather than in long vines, pinch off new growth any time throughout the year.

Common Syngonium Problems

Direct sunlight can burn syngonium's foliage, resulting in bleached leaves. If plants get weak and the stem between nodes becomes elongated, they likely need more light, advises the University of Florida IFAS Extension.

Avoid using cold water to water the plants in the winter; it can cause irregular water-soaked spots. If the leaves are warm but its leaves are cold, the plant may have a water imbalance. Symptoms include wet or water-soaked leaves. Prevent this imbalance by keeping the soil roots at a temperature of at least 65 degrees Fahrenheit. Be sure to warm the roots slowly to prevent shocking the plant.

Plants may experience nitrogen or phosphorous deficiencies, which you can correct by fertilizing it. Old leaves turning yellow is a common symptom of nitrogen deficiency, but it may also be a sign that the soil is too dry. Necrotic spots on the leaves and slower growth are symptoms of a phosphorous deficiency.

Syngonium Disease Management

A few diseases are common to syngonium plants. Bacterial blight and stem rot are caused by the bacteria Erwinia, advises PennState Extension. Symptoms include dark green spots on the leaves and a foul-smelling soft rot. Leaves take on a tattered appearance and will die if the stem gets infected. Erwinia can also cause bacterial leaf spot. The bacteria Pseudomonas spp. and Xanthomonas may also cause the disease. Symptoms include translucent spots on the margins of the leaves that turn green with yellow halos.

Discard any infected plants, and make sure new plants are healthy and disease-free. Avoid wetting the foliage and consider treating the plants with a bactericide to help prevent infection.

Myrothecium leaf spot caused by the fungus Myrothecium roridum can also be a problem. Leaf spots have concentric rings and range in color from tan to dark brown. Prevent this condition by avoiding injuring the leaves and don't over-fertilize with nitrogen. You can also use a fungicide to protect healthy leaves.

Pests Infestations and Treatment

Common syngonium pests include spider mites, mealybugs, aphids and scale. Infestations are rare if the plants has proper growing conditions and care. Spider mites are tiny, and they're not usually visible on the leaves. They cause stippled, yellowing leaves and perhaps even webs around the leaves and flower buds, advises Missouri Botanical Garden.

With a white, cottony appearance, mealybugs are easy to see on the plants. Aphids are about 1/8 inch long, and you may find them on the underside of the leaves. Symptoms of an aphid infestation include small leaves and a change in the foliage color. Scale causes leaves to turn yellow and drop from the plant. You also may notice white, gray or brown scaly bumps on the plant.

You can treat infected plants with horticultural oils or insecticidal soaps. Chemical options include Imidacloprid and Permethrin, notes Missouri Botanical Garden. Follow the package instructions for application and treatment.

Syngonium Warning and Safety

The syngonium plant, including its leaves, stems, roots and flowers, is poisonous when eaten and can harm people and pets, including cats, dogs and horses. The plant contains calcium oxalate crystals, and its poison severity is classified as "medium," advises North Carolina State University Cooperative Extension. Symptoms of poisoning include pain and swelling of the mouth, lips and tongue, difficulty swallowing and excessive drooling. Humans, dogs and cats may also experience vomiting.

Arrowhead vines can be an invasive species in some areas, including Florida, advises the University of Florida IFAS Extension. If you plant syngonium outdoors in these areas, make sure that it's not allowed to spread outside of your garden. In addition, be aware that the vine may climb trees, and the weight of the vines can damage the tree.

Control the spread of syngonium by pulling the vines by hand, making sure you don’t leave pieces of the vine in the soil. You can also use herbicides, but use caution as these can also damage desirable plants in your yard.