Despite what you might think, some cacti can grow stems that are very similar to leaves. Sure, this is exciting for cactus lovers. But it can also be alarming to see these unique cacti lose their leaves! It’s scary, however, knowing the reasons behind this will help you prevent those leaf drops.
Cacti can drop leaves due to 1) overwatering, 2) low light, 3) temperatures, 4) plant shock, and 5) rot. This can be prevented and corrected by 1) watering the cactus only when dry, 2) providing consistent temperatures, and 3) ensuring adequate sunlight exposure.
One of the primary characteristics of cacti is their leafless nature, and we’re okay with that. Yet when our uncommon cacti with leaf-like stems start to lose their leaves, we might not be as accepting! But you can relax, as you’ll learn more about leaf dropping by reading further.
Excessive moisture is the most likely cause of yellow leaves and leaf dropping in cacti. Cacti are typically drought-tolerant and must be allowed to dry between watering.
It’s important to remember that cacti generally don’t grow any leaves. However, there are a few cacti specimens that produce flat and individual stems which resemble leaves.
Study this more in Why Do Cacti Have Spines Instead of Leaves? (4 Reasons!)
Without a doubt, excessive water is the number one reason why these cacti suddenly drop their leaf-like stems.
Epiphytic cacti can be found in rainforests and have evolved to grow elongated stems that look like leaves. Some examples of epiphytic cacti are the zig-zag cactus, the mistletoe cactus, and the holiday cactus.
While they might have come from damp rainforests, it’s still critical not to overwater them!
Otherwise, their leaf-like stems will swell up with moisture and fall off the cactus over time if watered way more than necessary.
You can identify an overwatered cactus when its leaves are soft and yellow. Try to keep the soil on the drier side, and don’t water your cactus if it still feels moist.
Leaf drop can occur in cactus when it receives less than 9 hours of sunlight and is grown in overly shady conditions. Correct this by growing the cactus in a south or east-facing window with at least 9 hours of bright sunlight.
In as little as 21 days of being grown with inadequate light exposure, the cactus will become etiolated, or stretched, and lose its vibrant color.
While the ZZ plant might be happy in a shady corner, your holiday cactus won’t be as forgiving and will eventually lose its leaves.
A good rule of thumb is to ensure your epiphytic cacti receive at least 9 hours of bright but filtered sunlight. Be sure to let the cactus acclimate to the new lighting condition by slowly increasing the amount of light it receives daily.
Temperatures lower than 50°F will cause cacti to drop their leaves. Most epiphytic cacti, or cacti with leaf-like stems, cannot handle frost and must be kept warm.
When you think of frost-hardy plants, cacti are never the first examples to come to mind. If they’re kept too cold for too long, the stems and leaves of cacti will become soft and fall off from the lightest touch.
Even though some cacti are considerably resistant to the cold, like Gymnocalycium, epiphytic cacti are much more prone to cold damage than typical cacti.
Take the Rhipsalis baccifera, or mistletoe cactus, for example. It is a low-maintenance and popular cactus.
But because it comes from damp African rainforests, this cactus won’t survive in the cold as it has never experienced frost before!
If it is severely stressed, the cactus may even turn red. To help maintain all your epiphytic cacti maintain stems and leaves, shield your cacti from temperatures below 50°F or 10°C.
Cactus leaves can fall off as a result of plant shock. This often occurs in newly bought cacti or those that have been recently repotted, both of which are normal occurrences. Given proper care, the cactus will replace its lost leaves and continue growing.
Leafy cacti make some of the most interesting houseplants. They may be different from the typical spiky cacti. But this doesn’t mean they can’t experience plant shock like your other houseplants.
Similar to other indoor plants, cacti sometimes have difficulty acclimating to new and unfamiliar environments. A good example of this is right after repotting.
If the plant is healthy and only loses a few leaves, simply care for it as you usually do, and all will be well! Once it has grown accustomed to its new pot or home, it will replace all the leaves it has lost.
Pro Tip: Avoid moving Christmas cacti around frequently, as this will cause them to rapidly drop leaves and flower buds.
Rapid leaf drops and soft yellow leaves are signs that the cactus is rotting. Cacti suffering from rot must be saved quickly and moved to dry well-drained soils.
If your cacti are wilting and have mushy yellow leaves and stems, including their new growth, their roots may be rotting.
Remove it from its pot and inspect the roots. They should be firm and light brown but never black and soft. Foul-smelling roots and squishy stems are other surefire ways to confirm rot.
Most epiphytic cacti do not grow in pure soil. Since they often cling to different surfaces and grow upon rocks or trees, their roots are often quite aerated.
Because of this, they require generous drainage. After removing dead stems and roots, clean out its pot and consider using well-draining potting mixes.
Learn more in How to Trim Cactus Roots [5 Easy Steps + Video Tutorial]
Avoid using 100% potting soil and grow the cactus in at least 50% gravel or pumice. Hold off on the watering and in time, your plant might just bounce back and survive.
Fallen cacti leaves can be propagated while dead ones can be composted. Cut the leaves into small pieces and mix them with the compost for additional nutrients. Avoid using diseased or pest-ridden cacti leaves, as they can contaminate the compost.
If the leaves are still healthy, it might be possible to propagate them by burying the petiole or stem into some damp soil.
Aside from saving and propagating healthy foliage, these cacti leaves can be tossed out or chucked into your compost bin.
One of the great things about growing rainforest cacti with leaves is that many of them are spine-free, so you don’t have to worry about them shedding spines in your compost.
Pro Tip: Avoid composting anything from the Euphorbia family. These cacti produce toxic and milky latex that must not be added to compost.
After gathering the fallen cacti leaves, cut them up as finely as you can to help speed up the decomposition and mix it in with your compost. It’s a simple but unique material that can add plenty of nutrients and moisture to the mix.
But if you suspect the leaves fell off due to pests, disease, or rot, it’s best to discard them. Otherwise, your entire compost pile may go to waste.
Leaf drop in cacti is best prevented by 1) watering the cactus only when dry, 2) providing consistent temperatures, and 3) providing adequate sunlight.
Although not true leaves, the unique stem growth is what makes these cacti special. But they must be maintained. Otherwise, they will eventually fall off and die.
The good news? These cacti don’t require much maintenance, and only require you to follow these simple actions!
To avoid leaf drops in cacti, it is best to water them deeply only when the soil is almost completely dry. This will promote regular leaf growth and prevent the stems and leaves from dying.
Whether your cactus comes from a rainforest or a desert, it will most likely benefit from growing in relatively dry soil.
This is because the dryness improves the formation of rhizosheaths, which are essentially tough soil crusts that adhere to plant roots.
Rhizosheaths help reduce water loss and increase contact between plant roots and moisture in the soil, making it easier for cacti to access water.
Water your epiphytic cacti only when the soil is almost completely dry. You can insert a skewer or a finger into the soil to detect moisture. If they come out clean, the soil is still dry!
By following a regular watering routine, the pseudo-leaves of your cacti are less likely to fall off and leave your cactus bare. Plus, a healthy cactus is more likely to regrow its lost leaves and stems, making leaf drop less of a concern.
Rainforest cacti with leaves cannot handle frost and are best grown at 80°F. Move the cacti indoors during the winter and ensure they’re kept in warm rooms free of drafts.
About 10% of epiphytic cacti are found in warmer areas, so your rainforest cacti probably won’t respond well to a dry and cold winter.
If you like to keep your cacti outdoors, it’s still best to move them indoors during colder periods. Many epiphytic cacti, like the Thanksgiving cactus, grow best at 80°F (15°C) and make beautiful houseplants.
Beware of drafts, however, as these can cause the flower buds and leaves of Thanksgiving and Christmas cacti to fall off. These two plants are very alike but are two separate species.
Keep the windows and doors closed as much as possible, and be mindful of where your plant is growing.
Cacti are less prone to leaf drop when grown with 9–12 hours of filtered sunlight. For best results, keep indoor cacti near south or west-facing windows.
Like any other member of the Cactaceae family, your cactus will probably benefit from plentiful amounts of light.
Many leafy cacti thrive when placed 6 feet (1.83 m) from a west or south-facing window. But as always, it’s best to listen to your plant’s needs based on its unique environment.
For example, if your queen of the night cactus is growing well where it is, then don’t move it. An unnecessary environmental change could cause more leaf drops, so be careful!
When grown with at least 9 hours of bright light, your cactus should prosper for years.
It’s common for folks to give away 10 or 20-year-old holiday cacti to their friends and family. Given proper care, you might be able to do the same one day and share your cactus with your loved ones!
Are cactus leaves poisonous?
Most cacti are neither poisonous nor toxic to ingest and generally do not have leaves. Epiphytic cacti, however, tend to grow elongated stems that look like leaves. These cacti, such as the holiday cactus, are not toxic either and will not cause harm if eaten in small amounts.
Can I prune my cactus?
Due to the slow-growing nature of cacti, they are not commonly pruned. However, if the cactus is dying or its leaf-like stems are growing too wildly, it is possible to prune them. Cut off the undesired stems and leaves and propagate the cuttings to create new plants.
Is it normal for cacti leaves to fall off?
It is normal and even healthy for plants including succulents and cacti to occasionally shed their oldest leaves. However, it does not happen often with cacti. If the cactus loses more than one leaf at a time, the plant is most likely stressed and needs immediate care.
Cacti generally do not grow true leaves, but some species can form flat stems similar to leaves. These leaves can fall off due to excessive moisture from overwatering, low light, overly cold temperatures, plant shock, and rot.
Fallen cacti leaves can be propagated by placing it into soil or cut into small pieces to mix into compost. However, this can only be done with clean cacti leaves free of pests and disease.
To prevent epiphytic cacti from losing their leaves, water them only when their soil is almost completely dry and keep them at 60°F with 9–12 hours of bright, filtered sunlight.
- “Cacti: Biology and Uses” by Park S. Nobel in University of California
- “Cacti and succulents” by Deborah L. Brown in University of Minnesota
- “Holiday cacti” by Julie Weisenhorn and Mary Meyer in University of Minnesota
- “Christmas Cactus” by n/a in University of Florida
- “Rhipsalis baccifera” by n/a in NC State University