White Spots on Palm Leaves – Causes and Solutions

Palm trees in the landscape may look carefree, but they can get many diseases, bugs, and nutritional issues. Avoid many of these problems by following the recommended cultural practices that help keep plants healthy and vigorous. More information on how to grow outdoor palms successfully is provided in HGIC 1019, Palms & Cycads.

Leaf Spots: Palms are commonly affected by many leaf-spotting fungi. Leaf spots can be circular to elongated, brown, and possibly oily in appearance. It is difficult to differentiate among the leaf-spotting fungi by visual symptoms alone.

Prevention & Treatment: Don’t allow irrigation to wet palm foliage. In most cases, leaf spots will not kill the tree, and fungicides are usually not necessary. If the damage becomes severe, fungicidal sprays containing copper can be used (see Table 1 for specific products). If palm fruits are used for food purposes, copper fungicides are the only approved fungicides. Apply all fungicides at rates and spray intervals according to directions on the label.

False Smut: False smut or Graphiola leaf spot is caused by Graphiola species. This disease is most common in areas of high humidity. Only palms in the Arecaceae family are affected. This group includes the sabal palmetto (Sabal palmetto), the jelly or pindo palm (Butia capitata), the Chinese fan palm (Chamaerops humilis), and the Washington palm (Washingtonia robusta) in South Carolina.

Infected leaves have small, black, wart-like structures erupting through both leaf surfaces. Tiny filaments may emerge from the black spots. There are usually no symptoms on the youngest leaves.

Prevention & Treatment: Properly space palms so that there is plenty of air circulation to reduce humidity. Avoid wetting fronds during irrigation. Removal and destruction of severely infected palm fronds will help minimize disease spread. However, removing too many fronds may be more damaging to the palm than the disease. Palms are sensitive to nutritional deficiencies, and frond removal can worsen existing problems and weaken the tree.

Fungicides are usually not necessary but can be applied as a preventative treatment during the spring. Select a fungicide containing copper (see Table 1 for specific products). If palms are used for food purposes, copper fungicides are the only approved fungicides. Apply all fungicides at rates and spray intervals according to directions on the label.

Root of Ganoderma The first symptom of infection is withering and drooping of older fronds. Fronds collapse and droop parallel to the trunk. New growth is stunted and is pale green or yellow. The head of the infected palm may fall off or the trunk collapse. Depending on the point of invasion, the roots may be severely decayed.

Outer trunk tissues may seem solid, but affected palms have a hollow sound when tapped. Areas of dark brown tissue are evident when the trunk is dissected. Over time, conks (spore-producing structures of this fungus) may form. Palm death can take three to four years, depending on the tree’s age and environmental conditions.

Staying safe Do not hurt the tree in any way, especially when planting, staking, or using string trimmers and lawnmowers for regular maintenance. Ganoderma survives in the soil, so it is not recommended to plant another palm in the same location. There is no chemical control for this disease.

You can get bud rot from Phytophthora species, Thielaviopsis species, and some fungal pathogens. You can also get it from bacteria. Most of the time, bud rot happens after a tropical storm or a lot of rain. On the other hand, bacterial bud rot happens after cold weather damages the bud.

Regardless of the pathogen, disease symptoms are similar. Buds and young fronds show black lesions and young leaves wilt. A firm rot of the bud occurs. Over time, this area may become slimy later due to secondary invaders. Older fronds may remain green for several months and are the last to die. Eventually, only the trunk remains.

Prevention & Treatment: Avoid overhead irrigation when possible. Once infection occurs, plant recovery is unlikely. In general, infected palms should be removed and destroyed promptly to reduce disease spread.

Copper-based preventative fungicides can be used on plants that have the disease (see Table 1 for a list of products). Apply at intervals sufficient to protect new developing tissue. Apply all fungicides at rates and spray intervals according to directions on the label.

Palms frequently suffer from improper mineral nutrition in the landscape. The most common nutritional deficiencies of palms are nitrogen (N), potassium (K), magnesium (Mg), and manganese (Mn). Sometimes plants don’t have enough of other important nutrients like boron (B), calcium (Ca), copper (Cu), and zinc (Zn) if they aren’t in the fertilizers that were used, but this doesn’t happen very often in nature.

Lack of nutrients in the soil, an imbalance of nutrients, poor soil aeration, a high soil pH, and planting too deeply can all lead to nutrient deficiencies.

Not Enough Potassium (K): Not enough potassium is one of the most common and dangerous problems palms have in coastal South Carolina. Different types of palms have different symptoms, but the oldest leaves are affected first, then younger leaves as the deficiency gets worse. Typical symptoms are translucent yellow to orange spots that may be accompanied by black or necrotic spotting. Leaflets will usually have areas of necrosis (dead tissue) along their margins and tips. Symptoms are worse at leaf tips and margins and less severe at the base of the leaves. As symptoms progress, tips of leaves will appear withered, burnt, and frizzled. The midrib typically stays greenish-yellow for a period of time. Potassium deficiency can eventually be fatal to the palm.

Since potassium leaves sandy soils quickly, it is more likely for people to not have enough potassium in their bodies. In heavier clay soils, the rate of potassium leaching is reduced. Deficiencies in clay soils may be more due to insufficient potassium fertilizer applied. Many lawn fertilizers are high in nitrogen but low in potassium, which can make palm trees in lawns lose potassium. Palms need fertilizers that contain potassium as high as or higher than the nitrogen content. Fertilize all palms separately from the lawn.

Staying safe If you treat it, dead leaves won’t grow back, but new growth should get healthy and eventually take the place of the hurt leaves.

Manganese (Mn) Deficiency: Manganese deficiency can be fatal to palms. This is a common problem in high pH soils (above pH 6. 5) because manganese is insoluble at high pH levels. High water tables or poor drainage can also be to blame, as can too much phosphorus in the soil, which can bind up some micronutrients, especially manganese.

Manganese deficiency starts with interveinal chlorosis, which means yellowing between the veins, and interveinal necrotic streaking on the newest leaves. If the deficiency is advanced, leaves emerge completely frizzled, withered, scorched, and reduced in size. Manganese tends to leach more rapidly from sandy soils.

Staying safe For more information, see HGIC 1650, Changing the pH of Your Soil. Manganese sulfate applications to the soil or foliage can be used to avoid the problem. Two or three times a year, add 1 teaspoon of manganese sulfate to every gallon of water and mix it into the soil around the palm. Tecmangam and Southern Ag Manganese Sulfate are two brands of manganese sulfate.

Iron (Fe) Deficiency: Iron deficiency is primarily a cosmetic problem. Palms usually survive but will exhibit interveinal or general chlorosis on the newest leaves. Interveinal chlorosis is made up of green veins surrounded by yellow tissue. The newest leaves are usually the first to show this condition. As the iron deficiency gets worse, big parts of new leaves will die off at the tips, and the leaves will get smaller. Iron deficiency in palms usually happens when they grow in soils that don’t let air pass through (compacted or over-watered) or when they are planted too deeply. Palms that can’t get enough nutrients from the soil because their roots are damaged or not strong enough may not get enough iron. It doesn’t happen as often when the soil doesn’t have enough iron or when the pH is too high.

Prevention & Treatment: In alkaline soils, iron-deficient palms can be treated with chelated iron fertilizers. Iron deficiency symptoms can sometimes be temporarily eased by applying chelated iron or iron sulfate to the leaves on a regular basis. However, the problem will not go away until the soil is properly aerated or the plants are planted at the right depth. The rate of iron sulfate to use for foliar application is ½ teaspoon per gallon of water. Spray the foliage to runoff.

Nitrogen (N) Deficiency: Nitrogen deficiency is not a major problem in landscape palms unless soils are nitrogen-poor. Most palms generally require low levels of N, especially in comparison to turfgrass. Symptoms of nitrogen deficiency are uniform light green color foliage and a decrease in growth.

Nitrogen deficiencies are more common on light or sandy soils. This nutrient deficiency is most common in palms that are grown in containers. In landscape situations, potassium, manganese, and magnesium deficiencies are more common.

Prevention & Treatment: Treatment with any fertilizer containing N will quickly improve leaf color. The fertilizer nitrogen should be in a slow-release form.

Magnesium (Mg) Deficiency: Magnesium deficiency is never fatal and is primarily a cosmetic problem in landscape palms. Classic symptoms are marginal chlorosis on the oldest leaves, which progress upward to younger foliage. Magnesium deficiency is identified by a broad lemon-yellow band along the edge of older leaves that has a green center and a clear line separating the yellow and green parts. If the tips of the leaflets are also necrotic, which means they have brown dead tissue, this means that the leaves are lacking potassium. Like leaves that are lacking potassium, leaves that are lacking magnesium will not recover and must be replaced with new, healthy leaves.

Staying safe Epsom salts, also known as Southern Ag Magnesium Sulfate, are made of magnesium sulfate, which dissolves easily in water and moves quickly through sandy soils. But putting 2 to 4 pounds of magnesium sulfate on each tree and controlled-release potassium on it four times a year should stop any more symptoms from happening. If the soil pH is low, adjust using dolomitic limestone based on soil test results. If the soil has a neutral or alkaline pH, don’t use magnesium oxide as a treatment. It doesn’t dissolve well in high pH soils.

Boron (B) Deficiency: Boron deficiency in palms can cause leaves to appear small and crumpled. Other symptoms are sharp bends in the trunk with horizontal growth and bud necrosis or death.

Staying safe Sodium borates, boric acid, borax, or Solubar can be applied at 2 to 4 ounces per tree.

Palm nutritional deficiencies are easily prevented by following a yearly fertilization program. A complete granular fertilizer made just for palms, often called a “palm special,” should be used to feed mature palms in the landscape. ”.

Three to four applications of palm fertilizer are suggested to make sure the plant always has nutrients during the growing season. Be sure to only fertilize during the growing season (April through September).

According to the most recent research from the University of Florida, an 8-2-12-4 (N-P-K-Mg) fertilizer should be used at a rate of 1 5 pounds per 100 square feet over the area beneath the palm canopy. This fertilizer should be a slow-release form and should contain the trace nutrients listed above. Larger palm trees may have roots that grow 30 to 50 feet from the trunk. The whole area needs to be fertilized. If centipedegrass grows within 30 feet of the palm, you shouldn’t use more than 1 pound of fertilizer per 100 square feet of lawn, and you should only do this three times per season.

Adjustments for rates and distances will have to be made for newly planted palms. Newly planted palms should not be fertilized until after they put out a new spear. Be sure to fertilize only during the growing season.

The PalmGain 8-2-12-4 Plus Minors polymer-coated, sulfur-coated slow-release fertilizer has magnesium, manganese, boron, copper, zinc, sulfur, and iron. It is a well-balanced palm fertilizer.

If you can’t find a palm fertilizer, use a 12-4-8 slow-release fertilizer at the same rate every two months during the growing season. Apply Epsom salts at 2 to 4 pounds per tree during the in-between months of regular fertilization. Use a product like Southern Ag Essential Minor Nutrients that has the micronutrients palms need during the same months that you use Epsom salts.

Supplemental magnesium and complete micronutrient amendments in the fertilizer are important. It can take six months or more for a palm to get better after showing signs of a deficiency.

Nancy Doubrava, Former HGIC Horticulture Information Specialist, Clemson UniversityJames H. Blake, EdD, Extension Associate/Adjunct Professor, Dept. of Plant and Environmental Sciences, Clemson UniversityCarlin Munnerlyn, Retired Horticulture Extension Agent, Clemson University.

This information is given with the understanding that it is not meant to be biased. The Clemson University Cooperative Extension Service does not endorse any brand names or registered trademarks, and products or manufacturers that are not named are not meant to be biased either. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All pesticide use suggestions are only for South Carolina and were legal at the time of publication. However, state and federal regulatory agencies can change the status of registration and use patterns at any time. Follow all directions, precautions and restrictions that are listed.

White Spots On Palm Leaves – Popular Causes and Remedies To This Serious Infestation Sign

FAQ

How do you treat white spots on palm trees?

What does white spots on your palms mean?

How do you treat white spots on leaves?

What is the white disease on palm trees?

What causes white spots on palm tree leaves?

White spots on palm tree leaves can be caused by a variety of factors. One common cause is a natural substance called scurf, which appears as waxy white spots on young leaves. Fungal infections can also cause white spots, such as black sooty mold or Graphiola leaf spot. Scale insect infestations can also cause white spots on palm tree leaves.

What are the lumps on the palm of my hand?

Lumps are common in the palm. The most common cause is Ganglion cyst. These are sacs filled with fluid that arises from the joint or tendon and are non-cancerous. They vary in size and are sometimes painful. Nodules are another cause of lumps which are made of abnormal scar tissue. Most often the nodules are not painful.

How do you know if a palm tree has white spots?

The color of the white spots on the palm tree leaves can also provide clues about the cause of the spots. If the spots are white or gray, it may indicate a fungal infection. In contrast, if the spots are yellow or brown, it may indicate a pest infestation. 4. Look for Other Symptoms

Why are my parlor palm leaves white?

Parlor palm leaves may develop white spots due to a fungal infection or pest infestation. To care for Parlor palms, it is important to provide them with well-draining soil, regular watering, and bright but indirect sunlight. These palms are sensitive to dry air and may benefit from a humidifier or regular misting.

Why do areca palm leaves have white spots?

White spots on areca palm leaves and other species are typical because of environmental stress, disease, and pests. They develop spots that show as larger patches or small dots and can be brown, white, or yellow in color.

Do pygmy palm trees have white spots?

Immediately after seeing white or pale spots on your palm trees, isolate the trees if they are growing on pots or prune off the leaves with the spots. Remember that these spots may be scurf for pygmy palm trees, so you do not need to prune pygmy palms if they have natural spots.