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Fungal infections can diminish the charm of even the toughest plants, and cacti are no exception. Fungus on cactus is often seen as white or fuzzy growths on the plant’s surface, compromising its aesthetic allure and health.
While some fungi make plants look bad, others can hide in rot and destroy your cactus from the inside out. Thus, addressing such issues becomes critical to protect your plant’s beauty and vitality.
But what causes mold on cactus, and how can it be treated? Should there be any symptoms, and how can you prevent its damage?
That’s just what we are going to talk about today!
Fungus on Cactus: A Beginner’s Guide
There are plenty of good reasons to add cactus to your houseplant collection.
These plants are incredibly resilient and can forgive tons of neglect. Second, cacti come in various unique shapes and produce beautiful blooms, making your place look vibrant. Third, they are easy to grow and need minimal care, which makes them perfect for beginners.
However, despite their forgiving nature, cacti can also encounter issues affecting their growth and health. One such common problem is fungus on cacti.
This article aims to provide you with knowledge and helpful tips on identifying, treating, and preventing fungal infections in your cacti. We want to ensure your cacti stay healthy and happy in your home!
Here You Will Discover:
- The Causes of Fungal Growth on Cacti.
- Common Types of Fungi Affecting Cacti.
- Treatment Options for Fungus on Cactus.
- Preventing Fungal Growth on Cacti: Tips and Strategies.
So, let’s start!
Fungus on Cactus: Understanding the Causes
Before we talk about what causes mold on cacti, let’s see how to identify a fungal infection!
One of the common issues many gardeners face with their cacti is white fungus. If you notice a soft, white mass at the base of your cactus, the infection is in its early stages.
However, if you see this white mass on the stems, it means the infection is progressing and will soon hit your cactus roots.
The fluffy white mold grows on decaying plant parts, such as fallen leaves or flowers. Usually, it starts on the dead plant material and then spreads to the living parts of the plant.
So, what causes fungus or mold on cactus?
Well, many factors can contribute to fungal growth. However, improper watering and excessive humidity are the two main culprits.
Improper Watering Causes Fungal Growth
As we know, cacti are resilient, tolerant, and can live in varying conditions. Since they have meager watering needs, improper watering can harm your plant.
This is especially true if you overwater your cactus. If your plant has a poor drainage system, this can happen. In addition, the same can happen when heavy rains occur and you overwater your plant.
It paves the way for fungal growth, which can progress over time and attack your plant’s roots.
Beyond overwatering, poor cactus soil can also contribute to fungi growth, even if you don’t overwater your plant. This happens because your cactus lacks the nutrients essential for it to thrive.
Excessive Humidity: A Contributing Factor to Fungus on Cactus
Proper air circulation is critical to maintain humidity and keep your cactus happy. Humidity becomes a problem if your cactus is sitting in a small pot.
It happens when there is no room for air to circulate and reach the root system. As a result, your plant’s roots stay moist as they don’t get enough air to dry out.
If this is the case, you will see a cactus fungal infection arising on top of the soil near your plant’s base. The best way to prevent it from happening is to repot your cactus to a bigger pot with fresh cactus soil.
Temperature Fluctuations: A Cause of Fungus on Cactus
It is no secret that cacti are desert plants that love growing in warm temperatures. However, your cactus houseplants could fall prey to fungal diseases if your region has colder temperatures.
If you see mold on a cactus, move your plant to another spot where it can get plenty of heat and light.
Overfertilization Can Also Cause Fungal Infection
Your cactus can still thrive even if you don’t feed it with fertilizer. However, if the soil lacks nutrients, feed your plant with a cacti fertilizer with low potassium and nitrogen levels. Still, ensure that it is not overfertilized, which can encourage fungus growth.
Moreover, using overly acidic fertilizers with inappropriate pH levels can contribute to fungal infections. Optimal fertilizers for cacti feature low levels of nitrogen and potassium. Ensure the selected fertilizer is not overly acidic, as indicated by the pH level.
Different Types of Fungal Infections Affecting Cacti
Different types of fungal diseases can harm your plant. Here are a few common types:
Dry Rot: Do you see black spots and lesions on your cactus’s surface? If so, your plant might be experiencing dry rot. Dry rot is often caused by improper air circulation. The problem can occur if your pot is too small and there is not enough room for your plant roots to get some air.
Soft Rot: Is your cactus developing darker, sunken patches around its crown? If so, it is a sign of soft rot. There are many contributing factors to this fungal disease. These include overwatering, slow draining, cold temps, and bacterial infections.
Cotton Root Rot: Are there any brown strands on your plant’s root surface? If so, it is under attack from cotton root rot. Unfortunately, this soil-borne disease makes reviving or curing a cactus almost impossible. The best you can do is to replace your infected cacti with new plants.
Charcoal Spot: Are there any dark spots on your cactus? These spots are usually 1-4 inches in diameter and are called charcoal spots. Tiny fungal spores colonize the tissues and then start eating your plant.
How to Treat Fungus on Cactus?
So, can you treat mold on your cactus and bring it back to life?
Of course, you can if the disease is in its early stages. Remember, the key to getting rid of fungus affecting your plant is to identify the problem early. This means you must inspect your cacti more often to catch the issue as soon as it appears.
There are three main types of fungi in cactus. First, you can treat them with a fungicide spray; second, you need to remove the affected area; and third, there is no cure.
Fungal infections like soft rot are easy to treat with a fungicide spray if you catch it early. However, some fungi, like cactus anthracnose, need you to remove the affected area.
In this case, keep the following tools near you:
- Cactus-resistant gloves.
- Sterile knife.
- Rubbing alcohol.
First, put on your cactus-resistant gloves. Then, find the affected area and cut around it with a sterile knife. When removing the lesion, cut beyond its edges into healthy tissue to ensure complete infection removal.
Lastly, throw the affected part in the trash bin and keep the cut area dry. It can take several days for the part to form a callus.
Moreover, cotton root rot or charcoal spots are infections with no cure. Plants with these fungal infections must be removed before they spread to nearby plants.
- Do not overcrowd your cacti, as it can stop proper air circulation. Instead, space them out for adequate airflow and to reduce humidity levels.
- Before watering, ensure that your cacti are thirsty and that the soil is dry. Remember, damp soil is a favorite place for fungal spores to grow.
- Always use cacti-specific soil with good drainage. This helps prevent fungal infections caused by overly wet soil conditions.
- Fungi prefer high humidity, so checking humidity levels in your cactus-growing area is essential. This becomes even more critical if the area has poor ventilation.
- Fallen leaves and flowers around your cacti not only look bad but can also attract fungi. Thus, they should be removed, along with other plant debris, to reduce the risk of rust fungus.
- Are you planning to add a new plant to your collection? Quarantine it for a few weeks before introducing it to other plants in your home. This will ensure that your new plant is disease-free.
- Look for any signs of fungal infection, such as white or fuzzy growths on your cacti. If you notice any symptoms, take immediate action.
Video Credit: Peggy’s Plants
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This post aims to arm you with the knowledge to fight fungal threats and keep your beloved cacti healthy. We have also covered different fungal infections, what causes them, and how to treat them. At the end, we have practical tips on how to keep fungi at bay.
However, if your cactus is experiencing persistent fungal issues, let us know in the comments below. We will guide you on how to fix the problem so your cactus can keep thriving.
FAQs
Why does my cactus have red spots?
Red spots on cactus are often a sign of too much sunlight. Full sun for extended periods can stress your cactus, causing it to produce betalain. In addition, underwatering can also cause the problem. When your cactus is thirsty for too long, it shrinks, showing red spots.
Should I use neem oil to treat mold on cactus?
Neem oil can help treat common fungal infections. In fact, it is a natural fungicide that keeps fungi at bay. However, as with any fungicide, it works best as a preventative measure. Its efficacy will drop the longer you wait to remove an existing infection. In addition, if your plant has a severe infection, consult a plant expert or horticulturist.
Does stem rot require cutting away the infected tissue, or can it be treated with a fungicide?
It depends on the severity of the issue. For example, if the fungus has just started to develop, you can spray a fungicide to prevent it from spreading. However, if it has already developed, you might need to remove the infected tissue to stop its growth.
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