Curio Herreanus: How to Grow and Care For String of Watermelons

Do you love the look of String of Pearls but looking for something a little more unique? Curio Herreanus or better known as String of Watermelons, is a great choice. This succulent is low-maintenance, making it a perfect succulent for beginners.

They look great cascading down shelves, bookcases, or in corner plant hangers. But if you live in warmer regions, you can choose to grow outdoors in a rock garden, below trees and shrubs, or in planters. The vibrant green foliage is pleasing to the eye and will flow well in any space.

String of Watermelons goes by many names, such as String of Tears, String of Raindrops, and String of Beads. This succulent is similar to String of Pearls but has more teardrop shape leaves. Some leaves may have purple stripes, giving them the appearance of tiny watermelons. They produce small white flowers in the spring and summer.

A member of the Asteraceae family and formerly known as Senecio herreanus, String of Watermelons is a beautiful trailing succulent. They are native to the deserts of South Africa and Namibia. They naturally form a ground cover but are more commonly grown indoors in pots or hanging baskets.

You can plant them indoors or outdoors, but they are more commonly grown as houseplants. They look great in decorative pots as they trail down a shelf, bookcase, or plant hanger. If you choose to grow outdoors, use a ground cover in rock beds, wall crevasses, or succulent gardens.

Size and Growth

String of Watermelon is naturally a ground-covering succulent. They do not get very tall but can spread much, much further. The plant produces long, slender stems that can be 1 to 2 feet long in ideal conditions. The round leaves vary in size but typically don’t get larger than an inch.

The leaves will have purple, translucent stripes, which are similar to the stripes on a watermelon. These stripes will become a deeper purple when exposed to bright light. These stripes act as a window, allowing light to enter the leaf.

During the colder months, the plant will not grow as much as it is going through dormancy. You may not even notice the plant go through dormancy if grown indoors. It will continue to be green and healthy, just stop growing until warmer temperatures in the spring.

How to Grow

The care demands of this succulent isn’t as demanding as other houseplants. They require similar care to a String of Pearls or a String of Bananas. With that being said, it’s important to provide the proper care in order to maximize their lifespan. Let’s take a deep look into the care requirements that this trailing succulent needs to thrive.

Light

The most challenging aspect of growing Curio herreanus is providing them with enough sunlight. They have pretty high demands but may differ if you choose to grow them indoors or outdoors. If you choose to grow them outdoors, they will grow best in partial shade. Outdoor sunlight is unfiltered and more intense.

In their natural environment, the plant grows along the ground and receives shade from trees and other objects. When growing String of Watermelons, it’s best to mimic its natural environment as much as possible. Grow in the shade of trees, shrubs, and rocks to provide the plant some protection from the sun.

Many gardeners choose to grow Curio herreanus indoors. When growing indoors, you must provide the succulent with bright sunlight. Anywhere from 6 to 8 hours is best. If grown in too much shade, the plant will start to get leggy.

Water

Curio herreanus is a drought-tolerant perennial and naturally stores much of its water in its leaves. Storing water in the leaves allows them to go long periods without needing water. The water requirements are going to vary depending on whether you grow them indoors or outdoors.

On average you can expect to water your String of Watermelons every 7 to 14 days. If they a growing outdoors, this could be more frequent depending on the temperatures and rainfall received. If soils are dry to the touch and the first inch or more is dry, that’s a sign your plant needs water.

Water your succulents until you see water draining from the drainage holes in the container. This is a good sign that water is traveling through the entirety of the pot and that soils are thoroughly moistened. Allow soils to dry some between waterings to prevent overwatering. Over and underwatering your Curio herreanus can lead to numerous problems.

Soil

Like most succulents, String of Watermelon prefers well-draining soils that have a bit of gritty material added to them. Regular succulent potting mix works well, and most garden centers will carry it. These succulent soils typically have sand or perlite in them which is needed for the proper growth of succulents.

You can make your succulent soil by using standard potting soil mixed with perlite or sand. It’s important to have properly draining soils to prevent the development of root rot and other diseases. If growing outdoors, you may need to amend soils to ensure they properly drain.

Ground soil should be amended before planting because amended after planting can cause damage to the plant. Adding sand, gravel, or perlite to the soil will help prevent soggy soils. Soils should never be soggy as this can cause fungal diseases to develop. Check your soils often to catch any drainage problems and adjust them immediately.

Temperature

Native to regions where temperatures fluctuate, this succulent can withstand a wide range of temperatures. They have been known to survive temperatures as low as 25 F. This is rather surprising for a succulent!

Although they can withstand lower temperatures, they shouldn’t be kept at low temperatures for too long. Extended periods of cold can cause the plant to shut down and die. They should be kept somewhere between 68 to 95 F for the best growth and healthy plants.

A Curio herreanus can be kept outdoors in certain climates but pay attention to the weather. You may have to bring them indoors if temperatures drop too low. If you are trying to force dormancy, you can keep the plant at temperatures around 50 to 60 F. This will force the plant to flower in the spring.

Fertilizer

Curio herreanus can tolerate more fertilizer than most succulents. Feed on a biweekly schedule during the growing season. Choose a well-balanced liquid fertilizer or slow-release fertilizer. If you are using a slow-release fertilizer, you will only need to apply it every few months.

During the winter, you can low down on the fertilizer since the plant isn’t actively growing during the winter months. You can fertilize about every six weeks during the winter. Apply fertilizer at the soil level to avoid burning the leaves. Poor-quality soils will cause nutrients to deplete much more quickly.

Maintenance

String of Watermelons is noted for being low maintenance and easy to care for. That being said, they can’t be completely neglected and benefit from routine maintenance. Regular maintenance generates a happy and healthy plant. Let’s dive into how to properly prune and overwinter.

Pruning

This is a fast-growing succulent that grows up to 2 feet long in the right conditions. You can prune the plant anytime during the year but is best if done after it blooms in the spring or summer. Pruning will help you keep their shape and remove unsightly plant material.

This succulent is commonly grown in pots and spills over the top and cascades down. If your Curio herreanus is begging to get leggy or woody, this is a sign to start pruning. Leggy stems will have few leaves and large spacing between each leaf. Pruning is healthy for the plant and allows you to control the size of the plant.

Cut dead stems close to the base with a sharp pair of shears or scissors. You can cut off as much of the stem as you please. A cut should always be made near a node. Nodes are where new leaves emerge, and removing the node will result in no new growth.

Overwintering

In zones below a 9, you can grow them outdoors until colder temperatures set in. Once temperatures fall below freezing, you will need to bring your succulent indoors for the winter. Letting your plant sit outdoors in temperatures between 35 to 44 F can be beneficial if you want the plant to bloom.

If you want the plant to flower, place it in a non-heated area that gets at least 6 hours of light. Water about once a month during this dormancy period. Zones above a 9 can leave Curio herreanus outdoors year-round without the risk of dying due to cold temperatures. If you have no interest in the plant flowering, you can leave the plant in its permanent location.

Propagation

String of Watermelons can be propagated easily via stem cuttings. Propagation is necessary to keep the plant alive for years. They will only live for 3 to 5 years before you need to propagate. The best time to make the propagation is spring, summer, or early fall.

Begin by gathering the materials necessary to make the propagation. You will need clean shears or scissors, 4 to 6-inch pots, and succulent soil. Cut several 4 to 5-inch stems just below a leaf node. Remove the leaves on the button most leaves from the stem. You need to remove the leaves to allow roots to grow.

Lay the stems out to dry for 1 or 2 days before you start to plant. The area where you made the cut and removed the leaves needs to form a callous. Fill your pots with succulent soil. In the center of the pot, make a hole and place the cut end of the stem into the hole.

Pack the soil around the stem and be sure all leaves are above the soil surface. Wait a few days before watering.  Place in a bright spot and monitor moisture levels. It can take 3 to 4 weeks for the plant to begin establishing roots. Once established, resume care as normal and enjoy your hard work!

Potting and Repotting

If you need to repot, it’s best to do so in the spring. Use a well-draining succulent soil mix and a well-draining pot. Terracotta and ceramic pots are best for growing succulents. These types of pots allow for proper airflow and drainage. If you are using a pot that isn’t made of terracotta or ceramic, just ensure it has proper drainage holes.

Your pot should have proper drainage holes at the base. A lack of drainage holes can lead to root rot. You should choose the next size up from your current pot to allow for proper growth. Aim for one that is 2 to 3 inches larger and deeper. You can use a larger pot if you prefer but make sure it is larger than the current pot.

Fill the bottom of the new pot with soil, and gently remove the plant from the current container. Place the plant into the new pot and add soil around the roots of the plant. Fill the pot to an inch or so below the lip of the pot. Water lightly and monitor for signs of stress.

You can repot annually, but in 3 to 5 years, the plant will die back. Each time you repot the plant, you will need to increase the size of the pot. Before dieback occurs, it is best to propagate the plant to promote continuous growth.

Common Problems

Curio herreanus rarely have issues with pests and disease. This is what makes them such great houseplants for beginners and experienced owners as well. Many of their problems stem from improper growing conditions. Let’s take a look at a few problems you may encounter during their growth cycle.

Shriveled Leaves

Curio herreanus has large, fleshy leaves that naturally store a majority of the plant’s water. If you notice the once round leaves are shriveling, similar to a raisin, this is a sign of underwatering. Underwatering is a common problem but can be avoided. 

Soils should never be allowed to dry out completely between waterings. Once the top inch of soil should dry before you water again. Check soils often to ensure they aren’t drying out too much and too quickly. If your plant is struggling to retain water, consider changing the soil, pot, location, and sunlight exposure.

Yellowing Leaves

Yellowing leaves are a good sign that you may have an insect infestation. More commonly seen with sap-sucking pests such as aphids, mealybugs, and thrips. If you believe insects are eating away at your Curio herreanus, you should place it in quarantine.

Insects travel quickly from plant to plant and can affect other plants in your home as well. The moment you notice pests, you can begin treating. Treat with your preferred method until pests are gone. Research control methods for your specific pest infestation for proper treatment.

Mushy Stems

Mush stems are a great sign that you may be overwatering your String of Watermelons. Overwatering can lead to root rot which causes the stems to turn brown or mushy. The fungal disease attacks the root system and slowly moves its way up the plant.

This is preventable by watering on a regular schedule and observing soils for excess moisture. If you notice soils aren’t draining water properly, consider changing the soils. If you decide to change soils, stick with a succulent-specific potting mix.

Pest And Diseases

While fairly hardy, these succulents are prone to a few different pest and disease problems. Let’s take a look at the most common issues you’ll deal with during the life of your plant.

Root Rot

String of Watermelons are a rather hardy plant when it comes to pests and diseases. The plant rarely experiences problems when provided with the proper growing conditions. When something in the String of the Watermelons environment is off, the plant can develop contract diseases and pests.

The most common disease that affects the Curio herreanus is root rot. Root rot develops when soils are too damp or roots are exposed to standing water. The plant will slowly die from the roots up. Eventually, the disease will kill the entire plant. This disease is preventable and oftentimes, the plant can be saved.

This succulent prefers well-draining soils. Be sure to use the proper potting mix and plant into pots that have drainage holes. Check your soils to ensure they are properly draining and not becoming too soggy. If you are struggling with over-damp soils, consider transplanting to a new pot.

Aphids

The most common houseplant pest is the aphid. They have small lime-green bodies and tend to feed on the underside of new growth. Aphids are sap-sucking pests and will slowly kill the plant if left untreated. They may be difficult to identify at first but if you notice them, take action immediately.

Separate the infested plant and begin treating with your preferred method. They are numerous options for treating aphids, from home remedies to chemical insecticides. You can purchase treatments online or at your local garden center. Follow all label directions.

Mealy Bugs

Similar to aphids, these sap-sucking pests are tiny and difficult to identify. They multiply quickly and can easily spread from plant to plant. They have pale pink to almost white fuzzy bodies, and they hang out at the juncture of leaves or on new growth.

Mealybugs are difficult to control on succulents because the juveniles are so small and can hide in spaces chemicals can’t reach. If the infestation isn’t bad, you can wash away the bugs or remove them with your fingernail. For infestations that are extreme, use a cotton swab soaked in alcohol and wipe away the bugs and mold.

Frequently Asked Questions