6 Causes of Yellow String of Hearts (With Easy Solutions!)
The string of hearts, also known as the sweetheart plant, is widely beloved for its heart-shaped leaves. So why do the leaves turn yellow for no apparent reason? This is what I share with you!
String of hearts plants can become yellow as a result of overwatering, low light, underwatering, low temperature, and natural mutation. Older string of heart leaves will also turn yellow and fall off to preserve plant energy.
While there may be some reasons behind this discoloration that isn’t bad, yellow string of hearts leaves are usually a sign of something else. Let’s go over all the possible reasons your string of hearts is turning yellow.
Excessive moisture is one of the biggest causes for string of hearts leaves turning yellow. Overwatering can cause the plant to retain too much water in the leaves, leading to leaf drops and yellowing.
While there are always other factors, this is the most common reason behind yellow strings of hearts leaves.
String of hearts is a drought-tolerant and semi-succulent plant. To help it survive long periods without moisture, its heart-shaped leaves will collect and hold water.
If these leaves become yellow, oftentimes this is because the leaves are taking in too much moisture and the plant is being watered too much.
Yellow leaves will also readily fall off and look almost swollen. Overwatering this plant can be especially scary as it may quickly lead to root rot.
2. Old Leaves
Mature and older leaves on a string of hearts vine will eventually become yellow and fall off to allow the plant to focus on new growth. A few yellow leaves close to the plant base is normal and typically not a cause for alarm.
When happy, string of hearts is known to grow quite rapidly. Some owners share that their string of hearts, or rosary vines, grow an extra 5 inches (12.7 cm) after just a few months!
It’s not unlikely for the plant to reach several feet long. Because of this, however, the vines will develop more and more leaves.
To conserve energy, the older leaves at the top of the vine may eventually turn yellow and die.
If more than one or two leaves are turning yellow at a time, this could be something else. Otherwise, this is normal and is usually not a concern.
3. Low Temperature
Temperatures that average below 50°F can cause the string of hearts to become yellow and wilt. An outdoor string of hearts must be overwintered inside to prevent the plant from dying and the leaves from turning yellow.
The warmer it is, the more likely your string of hearts will thrive.
But if the temperature in your area is consistently below 50°F (10°C), the plant will start to weaken. Over time, the leaves eventually will turn yellow and if severe, the plant may potentially die.
Safe to say, this plant does not tolerate cold well.
Although it’s beautiful and can be used to decorate the outside of your home, it’s best to bring it indoors as soon as it becomes cold or before a harsh winter hits.
Dehydrated string of hearts will become yellow to signal their need for more moisture. String of hearts leaves that are lacking water will be wrinkled on the back. When older leaves at the top of the vine fold back easily, the plant is being underwatered.
This plant tolerates drier soils better than it does saturated soil. But it still requires water, no doubt!
You can tell a string of hearts is underwatered when the back of the leaves is wrinkled or shrivelled. The more yellow the leaves are, the more stress the plant is going through.
An easy way to identify a thirsty string of hearts plant is by doing the “taco test”. This is when you pinch the mature leaves closest to the roots like a taco.
If the leaves fold back easily, it requires more water!
Severely dehydrated string of hearts leaves will look dry and curly.
5. Low Light
Without adequate light, string of hearts plants will halt chlorophyll production, resulting in yellow leaves. This lack of light will prevent the plant from photosynthesizing and can potentially lead to the plant dying.
String of hearts, or sweetheart plants, can survive in less light than many other succulents. However, this does not mean it should be allowed to sit in continuous gloom.
If it’s left in an extremely dark area with little to no sunlight available, its leaves will become yellow. The same applies to cacti.
Exposed to strong sun, the plants’ leaves will become visibly darker as the green pigment becomes more prominent.
But if the string of hearts has no access to light, it will no longer be able to photosynthesize. Over time, it will stop producing chlorophyll, the compound that provides the plant’s natural green pigment and allows the plant to absorb light.
If there isn’t any more sunlight for it to absorb, there will be no more need to produce chlorophyll!
6. Natural Mutation
Leaves of the variegated string of hearts plants will sometimes be lighter or yellow on the edges. Additionally, these variegated string of hearts will produce pink or purple foliage. This mutation is normal and not a cause for alarm.
This is another common reason why the string of hearts leaves may turn yellow. It might be alarming but if this is a variegated string of hearts, this is perfectly normal!
Some variegated string of hearts will live up to their name—tinged with pink pigments.
If there is no issue with the plant and if it is only the leaf edges that are whitish yellow or pale in color, this could be part of the plant’s natural design. You can relax knowing there’s nothing wrong with your string of hearts!
4 Solutions For Yellow String Of Hearts Leaves
The yellowing of string of hearts leaves can be prevented by 1) providing sufficient water, 2) providing adequate light, 3) removing older leaves, and 4) adjusting the temperature.
So, you’ve identified the most likely cause behind your yellow string of hearts. Now all you need to do now is keep reading to learn exactly how to solve it!
1. Provide Sufficient Water
To prevent string of hearts leaves from turning yellow, ensure the soil is completely dry and water it only when the plant displays signs of dehydration. This will prevent overwatering and underwatering of the string of hearts. Reduce water in the winter.
One of the easiest ways to prevent and control yellow leaves is to make sure the string of hearts is properly watered.
By ensuring the plant is given sufficient moisture regularly, you can make sure the leaves do not turn yellow due to dehydration or overwatering.
Allow the soil to completely dry out before you water it. Consider using a moisture meter or a simple wooden stick to see if the soil is completely dry.
If the stick comes out clean, it’s ready for more water!
How often you may need to water your string of hearts depends greatly on the ambient humidity, size of the pot, and other factors.
Check out our article on how to water succulents and cacti the right way.
Moreover, be certain to cut back on your watering during the winter, when the soil takes longer to dry.
2. Provide Adequate Light
String of hearts must receive at least 4 hours of bright indirect light to ensure the green pigments remain and that the plant stays healthy. Plants must be allowed to acclimate to prevent potential plant stress and death from sudden changes in lighting.
Luckily, string of hearts is a rather versatile plant, so this should be one of the easier fixes. You can place your string of hearts in full sun or even medium shade, and it should do very well.
But as mentioned before, it cannot live in complete darkness.
To help care for your string of hearts, gradually move it to a brighter spot and allow it to adjust for at least one week.
This will help the plant get used to its new environment and ensure the plant doesn’t get stressed and potentially die.
3. Remove Old Leaves
Yellow string of hearts leaves can be removed to encourage new growth and prevent the plant from wasting more energy. Stop the plant from growing wildly by trimming the ends.
If your string of hearts has been with you for many years and its leaves are turning yellow due to age, you can simply cut off the older yellowing leaves.
This will help improve the appearance of your plant and help it conserve its precious energy for its other leaves.
If the plant is trailing and is already several feet long, consider cutting off the ends to help it from being overwhelmed.
To make it even better, you can use these same cuttings to propagate and make more string of hearts plants! This is a great method that covers two needs with one deed.
4. Adjust Temperature
Keep string of hearts plants in warm conditions above 60°F to prevent the plant from wilting and developing yellow leaves. Temperatures below 50°F can result in yellow foliage. Bring outdoor string of hearts in before frost and keep in a room with a heater.
Although this is a wonderful plant that does not require much maintenance, it cannot be left in environments colder than 50°F or 10°C.
So avoid leaving this out if you frequently have especially harsh winters in your area.
For string of hearts plants grown indoors, make sure the temperature is above 60°F. Check to make sure there are no drafts in the room, as this can easily chill the plant.
To help keep away the cool, check out this electric heater on Amazon. It’s great for indoor use and is even portable!
How do I make string of hearts purple?
Regular Ceropegia woodii plants cannot be manipulated to turn purple. However, there are some variegated cultivars that naturally produce pink or purple leaves. Variegated string of hearts plants can easily be found in many plant nurseries and stores.
Why are my string of hearts leaves small?
It is normal for the leaves of string of hearts plants to initially be small. As they grow older, the leaves will grow to be 1–2 cm wide and become more thick and fleshy. If the leaves do not grow and the plant continues to grow miniature foliage, this can be an indication that plant growth has stunted.
Summary of Reasons for Yellow String of Hearts
In general, string of hearts leaves will turn yellow due to overwatering, low light, low temperature, and underwatering. Discoloration caused by these factors is usually an indicator that the plant is suffering.
However, it is also common for string of hearts leaves to become yellow as a result of aging or natural mutation. These are normal and not any cause for worry.
Discolored string of hearts can be saved by watering them only when their soil is dry, supplying them with adequate light, protecting them from temperatures lower than 50°F, and removing yellow leaves.
- “String of Hearts, Ceropegia woodii” by Susan Mahr in University of Wisconsin
- “String of Hearts, Rosary Vine” by n/a in University of Texas