As Floridians we love our Palm Trees and when we picture our palm trees, we imagine them as tall magnificent trees with beautiful green fronds. So, the questions may be raised when you happen to look up at the tree in your yard and notice it is looking a little sad, yellow and unsightly. Why is my palm tree turning yellow? This is a very good question, and there are multiple reasons that your palm trees fronds could be turning yellow.
Since, there are more than one reason for why your palm tree fronds could be turning yellow the first step to diagnosing your palm tree, is monitoring your palm tree. If you notice new healthy growth, and the yellowing is only present in the older palm leaves your tree may just be getting ready for a trim. If the yellowing is progressive or is affecting even the newer healthy fronds you may have a more serious ailment such as a nutritional deficiency, mineral deficiency, bacterial disease, or an insect pest infestation. Accurate diagnosis will require a tree health care inspection from an arborist and soil samples will need to be taken.

Yellowing Palm Fronds, is it Time to Trim?

Unlike other trees, palm trees do not change colors with the seasons. However, as new growth develops the old fronds will turn yellow and then brown before needing to be trimmed. If it is a self-cleaning palm tree, the fronds will simply drop or fall off when they are ready. If you are going to trim your palm tree yourself, it is important that you do not remove the palm fronds too soon. Wait until the fronds have turned brown before trimming away, removing yellow fronds takes nutrients away from the other fronds and can affect the palm trees health. Additionally, when trimming your palm tree be sure to prioritize sanitizing your tools between each cut, to prevent the transfer of any possible diseases.

Nutritional & Mineral Deficiencies Cause Yellowing in Palms

Nutritional and mineral deficiencies are one of the most common causes for yellowing in palm tree fronds. Nitrogen is a common nutrient that supports the growth and development of palm trees, and plants in general. The most common reason for a nitrogen deficiency is using the wrong type of fertilizer, or not fertilizing enough. If your palm tree is being affected by a nitrogen deficiency, you will notice that the yellow affects all of the palm fronds, old and new. Your local arborist can give you guidance on what type of fertilizer to use and how often, based off the soils current nutrition levels and your specific palm trees nutritional needs.
Mineral Deficiencies
There are a few different minerals that could be deficient, causing your palm tree’s fronds to turn yellow. A soil test, performed by a trained arborist, is the only way to know for sure what specific mineral is deficient. However, we have listed a few of the possibilities below. Where the yellowing in the palm tree occurs can help you to determine what mineral may be lacking in the soil.

  • Potassium – Low levels of potassium will result in the older fronds, the palm fronds closest to the bottom, turning yellow. They may also develop yellowish-orange spots, if the problem isn’t corrected the yellowing will slowly move up the crown to the newer palm fronds. Having a tree low in potassium decreases its overall health and opens the door to pests and diseases.
  • Iron – Iron is an essential mineral that helps palm tree maintain their pretty green color all year round. The signs of low iron will show in the newer fronds first, to identify you will look at the ones in the middle of the crown. Poor drainage and over mulching are common contributors to iron deficiency in palm trees.
  • Magnesium – This deficiency is probably the easiest one to detect, because only the tips of the leaflets on each frond will turn yellow, usually it’s a brighter yellow color.
  • Manganese – Manganese deficiency will present with yellow streaks on the fronds, or palm leaves. The yellowing is progressive and as new fronds develop, they will have a singed look to them, called a “frizzletop”. If the deficiency is left untreated and becomes severe, it can be lethal.

Diseases & Pests cause Yellowing in Palm Trees

Diseases and insect pests are common contributors to yellowing in palm tree fronds. Unfortunately, not all palm tree diseases are correctable; however, they are preventable. Most diseases and insect pests are a result of an underlying health issues being a nutritional or mineral deficiency. Palm trees that are not getting enough nutrients and minerals are more susceptible to palm tree diseases and insect pest infestations. The best way to defend your palm trees against these issues, is with proper fertilization and preventative palm tree care.

Diseases

  •  Lethal Yellowing – A bacterial disease is spread by sucking insects, before the leaves turn yellow, the fruit or flowers will turn black (depending on which is present) and die prematurely. Beginning in the older leaves, the ones closest to the trunk will turn yellow and eventually turn to a grayish brown and completely dying. This disease can be treated with antibiotics by a trained arborist. If not treated before it reaches the spear leaf the entire tree will die.
  • Fusarium Wilt – This disease is not treatable and if your palm has these symptoms and a test confirms this disease, the palm tree will need to be removed and another palm should not be replanted in that area. With this disease the yellowing only presents itself on one side of the frond, the other sides leaves will be brown. You should also see a noticeable dark line extending up the petiole (shaft of the frond). Once all the leaflets turn brown the entire tree will die. Contact your local arborist immediately if you notice these symptoms.

Insect Pests

  • Spider mites – are a relative of the spider, so to protect themselves and their eggs they do spin webs. The spider mites look like yellow or brown spots on the leaf. They are extremely tiny and can be difficult to see, using a magnifying glass can help. If the palm tree is severally infested, its health will start to dwindle. The leaves will completely turn yellow and growth will cease. Consult an arborist for available treatment options.
  •  Palm tree aphids – Aphids, also known as palm leaf scale, are insects that look like bumps on a leaf. They have no head or legs. When they attache themselves to the palm leaf the suck the nutrients out, yellowing occurs around the area where they are feeding. The palm leaf scale releases a sticky substance called honeydew and then a black mold will grow on that. If you suspect your palm is infested with this pest seek help from your local arborist.

There are a variety of reasons for why your palm tree may be turning yellow. In order to properly diagnose your palm tree, seek the help of a certified arborist. Arborists are highly trained in tree health care and will use soil samples and evaluation to diagnose your tree’s ailment and recommend a treatment plan. Nutritional and mineral deficiencies are the leading cause for yellowing in palm trees, when left uncorrected they leave palm trees susceptible to disease and insect pest infestations, which can be lethal. The best defense against tree health care issues is prevention. So, speak with your Tree Medics arborist today by calling (813) 407-9974 and see what preventative tree care plan is right for you.