The bunny ear cactus is one of the more popular indoor cacti, its adorable name pertaining to its distinctive shape.
This cactus is perfect for beginner collectors because it is easy to care for and makes a great addition to your interior decor.
One of the most common problems encountered by bunny ear cactus owners is when their plant turns white.
The possible causes of a bunny ear cactus turning white are insufficient sunlight, too much sunlight, corking, fungal infection, frost damage, too much fertilizer, improper watering and chemical exposure.
In this article, we will discuss each of the possible reasons your bunny ear cactus is turning white, and how to fix each one.
If you are currently having this problem and you wish to learn more, just keep reading.
Why is my bunny ear cactus turning white?
1. Not enough sunlight
One of the most common reasons for bunny ear cacti to turn white is that they are not getting as much light as they need every day.
Remember that cacti, like all plants, need light to be able to photosynthesize and create chlorophyll. If they do not get enough light, they will lack this green pigment which is why they will slowly turn white or gray.
Cacti come from some of the sunniest places on earth, so they are used to growing under lots of bright light.
To fix this issue, simply transfer your bunny ear cactus to a place where it can get more light.
If the plant is kept outdoors but under the shade of a large tree, move it to another spot where it can get direct sunlight for a few hours a day.
If you are keeping the plant indoors, place it near a south-facing window. Normally, these windows let in light that is too harsh for most plants, but since cacti are desert plants that do well in full sunlight, they will do just fine next to a south-facing window.
If you live in an apartment that does not get a lot of light, or if you live in a place where the winters are dark, the plant might not be able to get enough natural sunlight. In that case, you can help the plant out by buying a grow light. Although natural light is always best, a grow light is a great alternative in times of need.
2. Too much sunlight
Even though the bunny ear cactus can tolerate direct sunlight better than most plants, this does not mean it should sit constantly under bright, direct sunlight. This could cause it to become crispy and white due to the sun’s UV rays burning it.
Too much sunlight also causes rapid water evaporation from all parts of the plant.
If your bunny ear cactus is turning white due to sunburn, relocate it to a different location where it will not get direct light for quite so many hours of the day.
As the plant recovers, also make sure you give it sufficient water to help rehydrate it.
3. The plant is corking
Corking is a natural occurrence in cacti. It happens when the cactus has reached a certain age and is large enough that it requires firmer support in order to grow any further. The tissue near the base of the plant becomes firm and bark-like, turning pale gray or white, and this discoloration can spread about halfway up the plant.
This is a completely natural thing to happen to a cactus, but if you do not like how it looks, you can always cut away the affected parts or start anew with another plant altogether.
You can tell that the cactus is corking by touching the discolored area. If the spot feels firm, then it is most probably just corking, but if the area is soft and mushy, the discoloration is due to something completely different.
4. Fungal infection
Another reason your bunny ear cactus is turning white maybe because it has a fungal infection. In this case, the discoloration is a sign of cactus erythema.
A fungal infection can affect any part of the bunny ear cactus, but it typically starts near the base.
The longer the infection is left untreated, the more soft patches start appearing between the joints of the plant. The joints are where the plant’s delicate tissue is located and these parts are the most sensitive.
Take the affected cactus to a different room, far away from your other plants.
To treat a fungal infection, remove the affected areas using a sterile knife and dispose of them properly, then treat the remaining plant with a fungicide to kill any fungi left on the plant.
Mist the plant daily with fungicide and make sure the room where it is kept has good air circulation.
While the cactus is being treated, it should still get lots of light.
Prevent fungal infections such as cactus erythema by placing the plant in a spot with lots of airflow and making sure that its soil is never waterlogged.
Standing water is a fungus’ favorite environment, so refrain from overwatering your plant so as not to encourage fungal growth.
5. Frost damage
As mentioned above, the bunny ear cactus is a desert plant and does not do well in cold climates.
An environment where temperatures can drop below 50 degrees Fahrenheit can be harsh for this plant. It may turn white when exposed to frost and if ice crystals form on its needles and body.
You may be able to save the cactus if the exposure was temporary and you were able to bring it indoors immediately, but if exposed to frost for an extended period of time, the plant may die.
If your bunny ear cactus is turning white because of frost damage, move it indoors and water it while exposing it to warm air. This is to try and bring the cactus back to life in a warmer environment.
If there are any dead branches on the cactus, prune them away using a sterile knife. This will allow the growth of healthy new branches unhindered by the dead ones.
While the plant is recuperating from frost exposure, make sure it is still able to get the amount of light that it needs every day, but do not overexpose it to too much sunlight.
After a few weeks of care, the frost-damaged plant should make a full recovery.
Prevent frost damage on your bunny ear cactus by taking it indoors even before the frost has begun.
The plant should still be watered to remain hydrated because winter air can be quite drying, especially to the soil in the plant’s pot.
If the plant is in the ground, protect it by placing mulch over the root area and insulating the entire plant with straw and burlap.
6. Too much fertilizer
Giving your bunny ear cactus too much fertilizer can also cause it to turn white.
Cacti do not typically need to be fertilized, because they can get most of what they need from their potting mix.
If you really want to help your plant out, fertilize it only once a year. If you fertilize more than once a year, then this is likely to be the cause of your problem.
If you think you are overfeeding your bunny ear cactus, stop fertilizing it immediately.
You can get rid of excess minerals and nutrients in the potting mix by flushing them out with water.
If you still want to fertilize your bunny ear cactus, do it once a year at half the suggested concentration on the packaging. But usually, as long as you are using a cactus or succulent soil mix, the plant will have everything it needs to thrive without extra feeding.
7. Improper watering
Both overwatering and underwatering can cause the bunny ear cactus to turn white. Because this plant is succulent, it is sensitive to too much water. Succulents are able to store water in their bodies for use in times of drought.
An overwatered bunny ear cactus will turn white as it wilts and as the excess moisture evaporates from its body.
An underwatered bunny ear cactus will also turn white as its spines and stems shrivel from dehydration. It will also start to droop and dry out.
If you have overwatered your bunny ear cactus, stop watering it immediately and allow the plant and its roots to dry out in a warm location with lots of light. Do not leave it out in direct sunlight, however, as a recovering cactus will be quite sensitive.
An underwatered bunny ear cactus will have to be watered immediately and generously. Water the soil in the pot until the excess water starts dripping from the drainage holes at the bottom of the pot. Place the plant back in a spot with good light and only water it again when necessary.
There is no set schedule to follow when it comes to watering a bunny ear cactus. Rather, touch the soil in the plant’s pot with your finger. If the top two inches of soil are dry to the touch, water the plant, but if the top two inches of soil are still damp, wait one or two days before checking again.
8. Chemical exposure
Exposing the bunny ear cactus to certain chemicals, like ammonia or bleach, can also cause it to turn white.
Ammonia and bleach can be found in most households and the plant can get exposed to them if you accidentally touch it after handling the chemicals, or if you use a container to water it that has been contaminated with the chemicals.
If you think that chemicals may have caused your bunny ear cactus to turn white, place it outdoors in the daytime and only bring it inside at night.
The time the plant spends outdoors will allow it to detoxify and the natural sunlight will also encourage photosynthesis, which makes it easier for the plant to get rid of the chemicals.
Wash the plant’s surfaces with warm water and soap and make sure you rinse it off well. This will help remove any chemical residues from the cactus.
The bunny ear cactus is a beautiful, low-maintenance cactus that has a distinctive shape, hence its name. It is a great starter plant for those that are just getting into cactus or succulent collecting.
One of the most common complaints among bunny ear cactus owners is that their plants are turning white.
The possible causes of this are insufficient sunlight, too much sunlight, corking, fungal infection, frost damage, too much fertilizer, improper watering, and chemical exposure.
The first step in fixing the problem is correctly identifying the cause so that the remedy will be straightforward and the issue resolved quickly.
Image: istockphoto.com / Emil Litov