Did you know that palm trees are, in fact, more related to grasses rather than trees? Because of this, they are likely to catch other diseases compared to usual trees, such as pines, maples, or oaks. Fortunately, healthy palm trees are quite resilient, but they might experience damages during transportation or winter. Find out more about these eight palm tree diseases and how to treat them!
1. Palm Leaf Skeletonizer
The palm leaf skeletonizer is essentially a caterpillar that eats the palm leaf. You can save your trees if you spot them early and remove the damaging caterpillar, and use high-pressure water to remove the larvae. If the infestation is already advanced, remove the affected leaves and wash the rest of the tree.
2. Bud Rot
Bud rot is quite common during humid, wet summers. It usually appears after excessive rain, but it may appear quicker if the palm tree was affected by very cold weather. Bud rot is caused by different pathogens, but the symptoms are the same. You will notice discoloration or event black lesions, followed by rot. If you detect it early, use fungicide on the bud to save the palm tree. If it is too late, you need to remove and destroy the tree.
3. Ganoderma Butt Rot
Ganoderma zonatu is a fungus that can infect nearly all palm tree varieties, but mostly older ones that are at least 15 years old. This infection withers old fronds while new ones stop growing. Affected trees might collapse while the roots decay. If you tap an infected tree, there is a hollow sound despite the healthy-looking exterior.
Ganoderma leaves in the soil, and, unfortunately, there is no chemical solution for this disease. You should destroy the tree, along with its roots. Do not plant other trees in the same spot; otherwise, they will also get contaminated. Make sure you remove all of your dead palms, stumps, and trunks from your landscape.
4. Leaf Spots
Leaf spots are caused by different fungi, so they differ in appearance, ranging from an oily look to brown, circular or elongated shapes. These spots will not kill your palm tree, and it is not necessary to use any chemical solutions. Make sure you do not allow any water to reach the foliage. If the disease becomes severe, you can use a copper fungicide. This is also food-safe, so you can still consume palm fruits.
5. Fusarium Wilt
Fusarium wilt is another fungus-caused disease. The main symptom is brown and discolored leaves. There is no cure for it, but you can avoid it by properly caring for your palm trees. Make sure you disinfect pruning tools between trees to prevent contamination. Water and fertilize your palm trees. Unfortunately, there’s no fungicide that can cure this disease.
6. False Smut
False smut is common in very humid climates and affects Aracacea family palms, such as Chinese fan palm, sabal palmetto, and Washington palm. You will notice wart-like structures on the leaves. These black spots might even filaments protruding from them.
To avoid this disease, make sure your palms are properly distanced so there is enough air circulation. Also, you can destroy the infected fronds, but too many of them might affect the palm’s health more than the disease itself. You can use a copper fungicide during spring as a preventative treatment.
7. Bacterial Bud Rot
Bacterial bud rot causes a wet blight. The affected leaf can be easily removed from the bud, and you will notice a bad odor because of the bacteria causing the disease. This is very common for palms damaged by cold. You can use copper fungicide on the affected bud.
8. Palm Aphid
Palm aphid usually affects young, new fruits. It is an insect that looks similar to whitefly with a distinctive white ring of wax. These sucking insects feed on the palm tree and produce honeydew, attracting fungi.
You can attract lady beetles to your palm trees to control the aphids. Alternatively, spray the aphids with insecticidal soap.