Cactus troubleshooting can be quite a challenge. If you’ve noticed unsightly brown spots on your cactus, fear not! There are several factors that could be causing the browning, including excessive light, overwatering, pests, diseases, or simply the natural aging process. In this article, we will explore the potential reasons behind the brown appearance of your cactus and, more importantly, how you can revive it.
Too Much Water Causing Cactus to Turn Brown
One common mistake in caring for indoor cacti is giving them too much water. Unlike other houseplants, a cactus actually thrives when slightly under-watered. Every drop of water is precious to a desert-dwelling plant like a cactus. So, when in doubt, it’s best to refrain from watering.
To prevent excess moisture, consider using a terracotta or clay pot. These materials help regulate water retention. If you notice your cactus turning brown, allow it to dry out completely before watering again. Don’t be deceived by the top layer of soil, as it may still be damp at the bottom. To check if it’s ready for watering, lift the pot. If it feels light, that’s a positive indication that the soil has dried out. Additionally, make sure the pot is not too large for your cactus; a slightly bigger pot than the root ball is ideal.
Not Enough Light
Insufficient light can also cause your cactus to turn brown. If you see long, leggy growth reaching towards the light source, it’s a sign that your cactus needs more light. Even if your cactus is placed near a sunny window, if the soil and the cactus itself are sitting too low in the pot, it may not be receiving adequate light. Over time, the soil can compress, so consider repotting your cactus with extra soil to bring it closer to the top of the pot.
Too Much Light
On the other hand, excessive light can also harm your cactus. If your cactus develops brown spots on its tips, it could be a sign of sunburn. These spots may appear dark yellow, brown, rust-colored, or even dark orange or red. To remedy this, simply move your cactus to an area with less direct sunlight.
Cactus Rot
If you notice brown spots on your cactus accompanied by soft and mushy areas, it’s likely a sign of root rot. In such cases, it is best to act quickly. Slice off healthy stems (without any signs of rot) and start a new plant. Before cutting, sterilize your tools to prevent further damage. After cutting, allow the stem to dry out, form a callous, and then replant it in fresh soil. Dispose of the rotted section, as saving the affected plant may not be possible.
Fungus, Disease, or Pests
Brown patches on your cactus could suggest the presence of fungus, diseases, or pests. If the affected area feels relatively hard like the rest of the healthy plant, it is likely due to fungus rather than rot. Using a fungicide can help prevent the patches from worsening, although the brown spots will remain as scars.
Hard brown spots on columnar cacti may be caused by a scale infestation. These pests suck the plant’s juices, resulting in brown spots. Removing the scales and applying insecticides like neem oil or bonide granules can help eliminate them.
If your brown spots resemble lesions or small holes, it might be a result of fungus due to cool and wet conditions. Although these spots won’t kill your cactus, they won’t disappear either. Keep an eye on them to prevent further deterioration. Additionally, small white bumps accompanying the brown spots indicate a mealybug infestation, which should be addressed promptly using effective methods.
Spider mites can also lead to brown spots accompanied by thin webbing. To combat them, spray a mixture of water and isopropyl alcohol onto the affected areas.
Cactus Corking from Age
If the brown areas are near the base or stems of your cactus and have a fibrous or woody appearance, it could be a natural process called “corking.” This occurs in mature cacti as a mechanism to strengthen their stems and support their growth. If this is the case, there’s no need to worry.
Final Thoughts on Treating a Cactus That’s Turning Brown
Identifying the cause of your cactus turning brown is crucial for effective treatment. Avoid trying random remedies, as they could potentially harm your plant. With proper care and attention, you can revive your browning cactus and restore its beauty. Remember to stay observant and address the specific signs and symptoms to ensure the best possible outcome for your beloved plant.
Stay Green!
