How to Grow and Care for String of Watermelon

The String of Watermelon (Curio herreianus) is a succulent originating from Namibia and South Africa, known for its cascading vines. Its most notable feature is the small, bead-like leaves marked with green and sometimes purple stripes, which resemble miniature watermelons. These leaves grow along slender, trailing stems that hang from baskets or shelves, making it a decorative houseplant.

String of Watermelon Care Guide

This plant thrives in bright, indirect sunlight. An east-facing window is an ideal location, while a spot a few feet from a south or west-facing window also works. This placement protects the leaves from direct afternoon sun, which can cause scorching. Insufficient light causes the stems to become elongated and sparse, a condition known as etiolation, as the plant stretches for a light source.

This succulent requires soil with excellent drainage, as a potting medium that retains too much moisture can lead to root rot. Using a commercial cactus or succulent mix is a reliable option because these are formulated to be porous. Alternatively, you can create your own mix by combining standard potting soil with an equal part of perlite or pumice to increase aeration.

This plant is more tolerant of dry conditions than excessive moisture. Use the “soak and dry” method by watering thoroughly until it drains from the pot, then allowing the soil to dry out completely before watering again. Check the moisture by inserting a finger an inch into the soil; if it is dry, it is time to water. During the winter, reduce watering frequency as the plant’s growth slows.

This plant is well-suited to average household temperatures, growing comfortably between 65-75°F (18-24°C). It can handle average humidity and does not require a moist atmosphere. The String of Watermelon is not frost-tolerant and should be protected from cold drafts and temperatures below freezing.

This plant is not a heavy feeder and only needs fertilizer during the spring and summer growing season. Apply a balanced liquid succulent fertilizer, diluted to half-strength, about once a month. Suspend fertilizing during the fall and winter when growth slows.

Repotting Your String of Watermelon

Repotting is an infrequent task, necessary every two to three years or when the plant shows signs of being root-bound, such as roots growing out of the drainage hole. When you repot, select a new container that is only one size larger and has a drainage hole.

Carefully remove the plant from its old pot and lightly untangle any circling roots. Place a layer of fresh, well-draining succulent mix in the new pot, position the plant, and fill the surrounding space with more soil. Wait a few days before watering to allow any damaged roots time to heal.

How to Propagate String of Watermelon

New plants can be grown from stem cuttings. Using clean scissors or shears, take a cutting that is at least four inches long and remove the leaves from the bottom inch or two of the stem. It is beneficial to allow the cut end to dry and form a callus over a couple of days, as this step helps prevent rot.

Once calloused, lay the cutting on top of a pot filled with well-draining soil or place the cut end in a jar of water. If rooting in soil, keep the medium lightly moist. If using water, change it regularly to keep it fresh. Roots will begin to form within a few weeks.

Common Problems and Solutions

• Mushy leaves or soft stems are a result of overwatering and potential root rot. Allow the soil to dry out completely and adjust your watering schedule.
• Shriveled or flat leaves indicate the plant is thirsty. A thorough watering should help the leaves plump back up.
• Leggy growth, which is long stems with large gaps between leaves, is caused by insufficient light. Move the plant to a brighter location.
• Mealybugs, which appear as small white cottony insects, are a common pest. Treat them by dabbing with rubbing alcohol or spraying with insecticidal soap or neem oil.