Pink rot fungus, also known as Gliocladium blight, is a palm tree disease that infects damaged or weakened palms. Like many fungi, it is easier to prevent than it is to treat. Here are some tips on dealing with pink rot on palms.
Pink Rot Fungus in Palms
You won’t see a healthy, robust palm tree planted in just the right place with pink rot fungus. Called an opportunistic fungus, pink rot likes to invade a plant that is already weakened by poor conditions or injuries. Here are a few situations that can lead to pink rot on palms:
- Palms that don’t get the right amount of sunlight
- Palms planted too deeply or not deeply enough
- Soil that is wet, poorly drained or compacted
- Too much, too little, or the wrong type of fertilizer
- Cold weather damage
- Palms poorly suited to the area
In addition to these environmental conditions, wounds can leave a palm susceptible to pink rot. Pruning away old leaves too soon creates a wound that serves as an entry point for disease. Remove leaf bases during warm, dry weather and only if they come away easily. Wounds caused by freeze damage and landscape maintenance injuries can also lead to pink rot.
Preventing Pink Rot Disease in Palm Trees
Make sure the soil drains freely before planting palms. To test the soil drainage, dig a hole about a foot (30.5 cm.) deep and fill it with water. Let the water drain completely and then immediately fill it again. The water level should drop between one and six inches (2.5 to 15 cm.) per hour.
Will the palm get the right amount of sunlight at the proposed site? The amount of sunlight or shade the tree needs depends on the species, so check the growing information on the plant tag. If the tree isn’t just right for the location you have in mind, consider another type of palm or a different site.
Fertilize palm trees with a special fertilizer designed for palms. Palm fertilizers contain the high concentrations of trace elements that palms need. Follow the package instructions regarding the amount of fertilizer to use and the frequency.
Make sure your climate is right for the palm you choose. If temperatures drop too low for the species, the resulting injury can encourage pink rot. A local nursery can help you find the right palm for your area.
Treating Palms with Pink Rot
The first step in treating the disease is to correct the stress condition that brought it on. If you can’t change the condition in the tree’s current location, you’ll have to decide whether you are willing to continue battling pink rot. If not, you may have no choice but to remove the tree and replace it with one better suited to the location.
There are a couple of fungicides that can help treat pink rot disease in palm trees. You should consider fungicides a temporary measure to help restore the tree while you correct the cultural conditions. Look for fungicide treatments containing thiophanate methyl and mancozeb.
Follow the label instructions and use these pink rot palm treatments on the area of infection. You can also use them as a preventative measure to treat wounds and after pruning.