Palm trees are a widely use landscaping plant both for indoor and outdoor landscapes. They are generally easy to care for and thrive with sunlight, warm temperatures and good soil. Most species of palm perform very well in southern Louisiana. When their leaves turn yellow to brown have many people at at a loss as to what to do.
There May Be a Problem With Your Palm's Diet
Palm Leaves Have Yellow Spotting
If your palm has yellow spots appearing on an otherwise healthy tree, it needs some potassium. Apply a slow release fertilizer with a good amount of Potassium. Potassium in the middle number in the fertilizer breakdown on the front of your fertilizer package.
Palm Leaves Have Yellow Stripes
If there are yellow stripes on the lowest and oldest leaves then your palm has a magnesium deficiency. Use fertilizer with added magnesium and some extra dolomite on the soil around the tree to turn the tree's health around. Magnesium will be listed as Mg on most packaging.
Older Palm Leaves Turning Yellow
When older leaves begin yellowing, there is a lack of Nitrogen in the soil around your palm tree. The tree is literally canabalizing its older leaves for the nitrogen in them to support new growth. A bag of fertilizer labeled for palm trees from any nearby hardware store should have the tree looking great in no time.
Your Palm Tree May Have a Bug or Fungus Problem
This probably means you are dealing with either a fungus or an insect.
Fungus will usually appear to be blotchy or spots of yellow on the leaves. An example of palm tree fungus would be fusarium wilt or bud rot. There may also be a powdery substance on the leaves. Insects will usually be accompanied by black soot on the plant, holes or tears in the leaves and damage to the trunk. An example of insects damaging to palms would be giant palm borers or thrips.
There Isn't Any Signs of Pests and the Soil is Fertilized
The palm has proper nutrition, but the leaves are still turning brown. This is natural. as long as the transformation is fairly even. The leaves will eventually turn brown as part of the tree's life cycle. There is no need for them to turn prematurely though. Keep your palms fertilized and they will stay looking good for a much longer duration.
Pruning Palm Trees
In best practice, you should not prune the leaves off the palm until they are completely brown. Doing so removes some of the nitrogen and other nutrition stored in the plant. That being said, a lot of people do not want leaves on their palms to be any color but green. If you are one of these people, you can prune the lower yellowing leaves off as long as your have the soil properly fertilized. If the leaves at the top of the palm are yellowing, you have one of the problems mentioned above. If you begin seeing other leaves yellow soon after pruning, your soil may not have had the correct amount of fertilizer.
When pruning your palm, be sure to follow the same pattern of cut as all of the other branches have been cut so the trunk of the tree is uniform. Usually all you will need is protective glasses, a hat, gloves, a pair of loppers, a ladder and someone to hold it for you. If it is your first time pruning a palm, remember to take your time, be careful and it will probably take you a lot longer per tree to prune than you originally thought, especially if its been a few seasons since you pruned last.