Even though cacti are tough plants, things can go wrong sometimes. Yellow leaves are a common result. However, it’s essential to remember that it’s a symptom. It’s not necessarily diagnostic of a specific cause. Getting your Barrel Cactus or San Pedro Cactus on the mend is a process of elimination. Fortunately, there are easy fixes from many common issues.

Dormancy

Many indoor cacti undergo a period of dormancy during the winter month. Shortening days usually trigger it. It’s not unusual for a plant to drop a few leaves or yellow. We suggest keeping an eye on it and determining if anything else is causing it.

Overwatering

If you’re just starting with cacti, it’s easy to get watering wrong. Remember that some species grow in environments that may only get a few inches of rain a year. You should only water your plants when the soil feels dry. Alternatively, you can use a moisture meter to make sure you’re taking care of them properly.

Low-Light Conditions

Some plants are surprisingly tolerant of low-light conditions. However, that’s probably not the case with most cacti. Many of their habitats average five or more hours of sunlight a day.

Plants need sunlight to conduct photosynthesis to produce energy. Luckily, you may find that moving your Montrose Cactus to a sunny room will fix the problem.

Too Much Sun

Sunlight is a good thing—as long as it isn’t direct light. Ironically, cacti can get sunburn. Bear in mind that many species don’t have large leaves to shade themselves.

Excess sun is a potentially serious issue, too. The outer layer protects the plants from water loss. Any damage on the outside of the cactus could leave it vulnerable to disease.

Stress

Many cacti live in relatively stable environments without significant seasonal changes. That life history means they aren’t adapted for handling change well. Frequently repotting or even moving your cactus could stress the plant, causing the yellowing. The best thing you can do for your cacti is to replicate the environment in which it evolved.

Nutrient Deficiency

Some cacti may develop nutrient deficiencies if you have repotted them in a while. Not giving them fertilizer occasionally can also cause it. An iron deficiency or chlorosis is a common problem with these plants. Giving your cacti a product formulated for these species will fix it.

Disease

Disease can also bring on yellowing. Root rot is a common culprit. It impairs your cactus’s means of transporting water and nutrients as it decays. The fungus will spread, causing further damage. The plant will likely die unless you take action quickly.

Pests

Cacti are hardy plants. However, pests, such as mealybugs and spider mites, can wreak havoc on houseplants. It’s essential to identify the insect correctly. You can then apply a pesticide that targets the problem.

Final Thoughts

While yellowing can have benign causes, it can also signal trouble. Luckily, many issues are easy to remedy. It’s simply a matter of paying attention to the clues and giving your cacti what it needs to survive.