North Florida Tropical Landscaping
February 22, 2021
The Sago Palm, or cycad as they're also known, is one of the Earth's oldest plant species dating back to the Triassic and Jurassic periods. This makes them tough and durable, but not without their enemies, and scale is one of their primary challenges.
Treating the sago palm scale can be done naturally by pruning and scraping infected fronds, applying neem oil, or using insects like ladybugs and parasitic wasps to attack the scale; it can also be done chemically using insecticides like horticultural oil.
Treating cycads for scale takes time, some work, and mostly patience, understanding what scale is , how to diagnose the two different kinds, and then deciding on the best course of treatment and prevention.
Many people believe that scale may be a bacterial condition, but these are insects that attack the plant and consume the sap. Essentially parasites, the sago palm scale has two common varieties: the Asian Cycad scale and the Oleander scale.
The Oleander scale feeds on the top of the fronds, while the Asian scale feeds on the underside. These insects grow under a protective wax shield resembling reptilian scales, hence the name.
If you see a frond with a white covering, this indicates severe infection, and scraping the frond will tell you if the scale is alive or dead. If the residue is dry and powdery, the scale is dead; the insects are still alive if wet and mushy.
Larvae hatched under the scale eat the tree sap and excrete a honeydew sticky yellow substance. This, in turn, attracts ants, flies, and various other insects.
The honeydew also traps dark fungal spores, preventing light from reaching the leaves and interfering with photosynthesis. While the scale may not often kill full-grown cycads, it can destroy young trees in a few weeks.
If you notice scale symptoms on your cycads, you need to act immediately, so let's look at the natural and chemical methods to treat sago palm scale effectively.
There are some easy ways to treat sago palm scale naturally without pesticides, and we will look at those in this segment.
Start with pruning your infected sago palm. You need to remove all the infected fronds and place them in a plastic bag. If you notice any fronds with developing scale or ones that look sickly, then remove those too.
Ensure you discard these away from other plants to prevent the infestation from restarting.
If you can see that the infestation is light or just beginning, then use a plastic implement like a credit card or another blunt garden tool to scrape it off. Please wash your hands afterward to ensure you don't spread it through contact with healthy fronds.
Isopropyl alcohol is available from your drugstore and is cheap and effective when used as a 'dab' on the scale insects. You can dip cotton wool in the alcohol and then lightly dab the scale to kill and remove it.
You can also use the alcohol-soaked cotton ball to scrape off the scale as this will also remove the honeydew, and if you do this treatment every 2-3 days, the scale infestation will die.
These soaps are very effective as they kill the scale and leave a protective layer on the plant to prevent the scale from reoccurring. The soap kills the scale by suffocation as it blocks the respiratory spores on the insect.
You will need to wash the cycad to remove the soap after each application to ensure that the plant's pores aren't blocked.
Neem oil is a natural organic pesticide derived from the seeds of the neem tree that effectively treats sago palm scale.
Ensure that the neem oil contains azadirachtin, slowly killing the scale and leaving a protective layer on the plant's surface afterward. Mix the oil with water following the directions and spray the plant thoroughly.
Tip: When spraying, do it early in the morning when the temperature is above 70F and below 90F, as these are the optimum temperature ranges for effectiveness.
One of the better ways to treat this infection is by introducing predator insects that feed on the scale. Ladybugs are not only great for your garden but are voracious eaters of scale insects, and they are entirely harmless to people, pets, and surrounding plants.
Parasitic wasps are another scale predator species and will also be effective as a predator to destroy scale and are harmless to humans and will only sting when mishandled.
Where possible, go with the natural remedies, but if required for severe or stubborn scale infestation, there are chemical solutions too.
Horticultural oil is an example of a systemic insecticide that will effectively remove scale infection as it can be used as a spray or a drench.
This oil is better than most as it poses little to no threat to bees and other insects but requires safety wear during application. You need to be dressed in long pants and a shirt with long sleeves, chemical-proof gloves, protective eyewear, and a respiratory mask.
If carried out incorrectly, chemical treatments for any plant conditions can cause damage to your other plants, native wildlife, or other people so do take. If you ever need help or professional advice, you can always reach out to the team here at LawnMore.
Mix the oil according to the instructions and spray each part of the plant thoroughly. Lift the fronds to spray the underside and then the top, the base of the palm, the crown, the cones, and all the tiny spaces in between.
Every alternate month, you can spray the soil around the tree's base to prevent scale nymphs from entering the root systems.
Temperatures above 70F are recommended for this spraying application as well. Also, remember to discard any remaining solution safely where it will not come into contact with the water supply.
With the choices available using either organic or chemical solutions, the sago palm scale should never be an issue again with your beloved cycads. Nature's time clock runs a little slower, so don't expect instant results from treatments.
Be thorough and patient and use the natural options first to mitigate any risk to other plants, people, and pets while removing this pest. Think about how great it will be with your cycads free of scale and a colony of ladybugs resident in your garden!
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