Is the newest growth on your sago palm turning yellow, brown, frizzy looking and dying – is it a pest or disease or something else?
Photo credit: Mary Derrick
This sago palm is suffering from a classic case of manganese deficiency. When sago palms lack manganese, the newest leaves will develop yellow splotches or be entirely yellow. As the leaves die, they turn brown and take on a frizzled appearance. Sometimes the leaves or fruit may be smaller than normal. If left unchecked, the sago usually dies.
Manganese is a micronutrient required by all plants for normal, healthy growth and is most available for plant uptake when the soil pH is between 5.5 and 6.5. Soils in the Florida panhandle are often naturally low in manganese and then what available manganese is present can be unavailable for the plant to use if the pH of the soil is much above 6.5. Also, manganese tends to be leached from the soil when the pH is below 5.5. Soil pH and nutrient testing is useful to determine if soils are nutrient deficient. Contact your county Extension office for information on getting that done.
[notice]Before treating, rule out an infestation of Asian cycad scale. Click here for a UF IFAS Extension publication on this damaging insect. Be aware that both are common problems for sago palms and that your sago may be afflicted with both![/notice]
If this is happening to a sago palm, the good news is that it is easy to correct. Manganese sulfate is readily available at garden centers, feed &seed stores and independent nurseries. Just make sure to get manganese sulfate and don’t confuse it with magnesium sulfate (Epson salts). The amount of manganese sulfate necessary to correct this deficiency will vary with its size, soil type and pH. Sago palms in sandy, acidic soils require less manganese sulfate than those in high pH soils. One ounce is sufficient for a very small plant in sandy, acidic soil. A very large sago in a high pH soil may require about five pounds, however. Spread the product evenly over the root zone and water in with about a half inch of water.
The affected leaves cannot be cured but new growth should return to normal. If the new growth is still affected, an additional application of manganese sulfate may be needed. Once sago palms have suffered from a manganese deficiency, half the initial rate should be applied yearly to prevent the deficiency from re-occurring.
Even though sago palms are not true palms – they are cycads – their nutritional needs are very similar to palms. Most of the time they grow well without any supplemental fertilization, but if they do need fertilizing, use a 8-2-12-4 (the fourth number is magnesium) palm fertilizer with micronutrients and avoid using other fertilizer products in their root zones.
For more information on sago palms please see:
- Sugar Belle Mandarin: A Great Choice for the Florida Panhandle - November 22, 2021
- LandscapeQ & A - August 20, 2021
- Let’s Talk Beneficial Insects - August 18, 2021