Many popular flowering plants owe some of their fame to their uses and beauty. As a result, such plants have become a staple in gardens across the globe, often bringing with them various problems.
Take, for example, hibiscus (Hibiscus sp.) seedlings. Hibiscus produces beautiful flowers that brighten up any garden, attracting bees, butterflies, and hummingbirds.
The flowers can be dried and eaten or used to make tea. But hibiscus is also prone to some really nasty diseases that can be caught from – or spread to – other plants in your garden.
One such disease is Anthracnose, a highly contagious disease that can quickly spread throughout your plant collection and isn’t always easy to treat.
In this article, we will delve into effective ways to fix Hibiscus anthracnose. Read on to learn more.
What Causes Hibiscus Anthracnose? And How to Fix It?
When you see unusual spotting on your hibiscus plant’s leaves, there’s a possibility it has contracted Anthracnose.
Let’s take a closer look at what this disease is, what it does, and what to do if your plants contract it.
What Is Anthracnose?
Anthracnose is a disease caused by several fungal species, most of which are in the Colletotrichum and Gloeosporium genera.
The exact species isn’t important, as this fungal disease tends to have the same symptoms and treatments regardless of which fungal strain causes it.
When an infection is suspected, it’s important to treat the plant immediately to reduce the risk of spreading.
Symptoms Of Anthracnose
Diagnosing this disease early on can be difficult, as the symptoms resemble many other common diseases.
Dark brown spots on the leaves, stems, and petioles are generally one of the earliest signs.
Spotting is more common on new leaves and shoots than the hardier mature ones. The spots will break open as the disease progresses, leaving irregularly-shaped lesions.
These lesions can become necrotic over time and cause dieback if a stem has severe lesions.
Mature leaves which are infected may suffer from leaf curl and eventually become necrotic.
The plant may suffer from stunted growth, leaves can fail to open, and stems may split due to the lesions.
Lesions on the undersides of leaves tend to ooze pink or orange spores, which is often one of the most telling signs that a plant has this particular infection.
How Does Hibiscus Contract Anthracnose?
Anthracnose spores are extremely light and have evolved to spread easily, although they also have a slightly sticky nature to prevent the spores from being dislodged by strong airflow.
One of the most common means of contamination is through water, and a single drop of dew or water can transport spores from one plant to another.
Cross-contamination is also very common when touching an infected plant with your hands or tools and failing to sterilize immediately afterward.
Another common source of contamination is reusing contaminated soil or allowing infected debris to come in contact with an uninfected plant.
Finally, seeds and any other parts of the plant that might be used for propagation could be infected and cause any newly propagated plants to have the disease.
How To Treat Anthracnose On Hibiscus Plants?
You will need to prune away any diseased leaves or branches.
Here’s what you need to do:
- Use sharp, sterile shears and sterilize them between each cut.
- Make sure to dispose of every cutting in a secure bag to be burned or otherwise safely destroyed.
- Be sure to also wash your hands thoroughly after working with a diseased plant.
- If the hibiscus plant is potted, you will also want to replace the soil, destroying the infected soil.
A quality fungicide will help bring anthracnose under control, and copper-based fungicides tend to work best.
A treatment schedule of 7 to 10 days, as opposed to every 14 days, has been known to improve the efficacy of fungicides when treating this disease.
You will want to check the label before applying any product this frequently to ensure this schedule will be safe.
You can also look for fungicidal sprays that contain specific chemicals known to be effective against Colletotrichum and other anthracnose-causing fungi, such as:
- Chlorothalonil + thiophanate methyl
- Pyraclostrobin + boscalid
Of course, prevention is the best medicine, and there are some ways to minimize the risk of an anthracnose infection.
Proper watering methods are essential, as spraying plants with water can result in sunburn (if done at the wrong time of day) and can also become a breeding ground for fungi.
The water droplets also create an increased risk of causing cross-contamination when the wind blows.
While it won’t completely prevent or cure anthracnose on its own, treating our hibiscus with a neem soil soak every 2 to 3 weeks can help control this disease.
Neem oil has been found to contain some antibacterial and antimicrobial properties.
When provided as a soil soak, it becomes a systemic insecticide that attacks anything breaking through the plant’s “skin.”
This includes fungal infections such as anthracnose, which are not surface-based.
The neem may slow the spread of anthracnose within the plant, although how effective it is will depend on many variables.
However, the fact that it can help against anthracnose while providing many other benefits to your plants is enough to justify its use as a partial preventative.