Scale Orchids: The Common Reasons And The Right Solutions

Scale orchids are disturbances on plants that cause an issue that can happen due to multiple reasons, such as bringing an infested plant home, not caring for your orchid plants properly, scales being attracted to the thin leaves, and the use of pesticides. If you do not know the reasons for your orchids, our experts are here to help you!

Reasons to Have Scale Orchids

Read on as we discuss these reasons in detail and solve the matter once and for all.

What Are the Reasons to Have Scale Orchids?

The reason to have scale orchids is that you would purchase an infested plant from the start, or have an under or over-nourished plant. It would also be due to the attack on the thin foliage, or the frequent use of pesticides.

– Purchasing an Infested Plant

The most common way of acquiring scales is by purchasing an infested plant. Scale is easily transmitted to clean plants when plants are crowded. For this reason, isolating new plants for at least two to four weeks after bringing them home is always recommended, because you never know if it already had ones and even gave them to the rest of the surrounding plants.

It can take days before a pest infestation is observable, even though mature scale can crawl from plant to plant, which is how scale spreads from an infested plant. If a healthy and uninfected plant is placed near an infested plant, the scale can move to the new and healthy plant. This infestation can happen easily in settings where orchids are placed close to other orchids and plants, such as in the flower shop, grocery store, or greenhouse.

Scale can travel through air currents, which is why they are very common to have them. It is a simple way for scale to be transferred between outdoor plants. Air and wind currents carry the scale around the garden, allowing them to infest new plants. It may be how your outdoor orchids become infested with scale pests. In greenhouses, air currents within the greenhouse make it easier for pests to travel and infest new plants.

– Under or Over-nourished Plants

Scale pests attack orchids because orchids are stressed and weakened due to poor growing conditions. Orchid leaves lose their attractive appearance and turn wrinkly when you do not water them enough. The worn-out leaves are a great source of attraction for the scales, so the over-fertilization can make leaves brown and damaged and tackle the plant.

Scale pests spread to other plants from the affected ones by crawling from one plant to another. Orchids start shrinking with time if they are not getting enough light, water, temperature, humidity, and nutrients. In this case, you must know that the ideal humidity for most of these plants, and most orchid plants, is from 50 to 70 percent, and possibly more during hot seasons. However, if the humidity increases, it’s favorable for the scale pests.

The leaves change their color with the change in the light; too much light can make them turn yellow. Not getting enough light usually causes dark foliage to develop, but if your orchid leaves are very dark green, it’s a sign that they are unhealthy and not getting enough light.

– Scales Are Attracted to Thin Foliage

Scale pests are attracted to orchids because they feed on the sap of orchids, which is full of nutrients. Orchids are attracted to the fluid extracted by some orchids when they flower, and they are highly attracted to Cymbidiums orchids, which are considered host orchids for scale pests. This is because these parts are thinner, as their foliage is what they are going to be eating.

Scales Are Attracted to Thin Foliage

What happens is that they would begin to suck the sap out of plants, which can cause deformed leaves, causes yellowing of leaves, brown pockmarks, and causes leaves to fall off. Without mediation, the plant will eventually die off, and now, the orchids are easily exposed to scale pests because of their thin and delicate leaves.

– Frequent Use of Pesticides

Scales are tricky, and they’re generally resistant to most pesticides. Harmful chemicals cannot penetrate the hard outer shell of scale pests but cause the death of many natural predators like parasitic wasps, including species of Coccophagus, Aphytis, Metaphycus, and Encarsia.

Insecticide applications may reduce the number of scale pest predators, which allows scale pest populations to increase potentially and rapidly and causes yield loss. However, if you haven’t been cleansing your plant’s leaves they will come along and mature, increasing in their number.

How to Get Rid of the Scale on Orchids?

To get rid of scale on orchids, you should first isolate the plant, and apply some rubbing alcohol or neem oil to them. Then, make sure to know the needs of the plant, spray some insecticidal spray, and repot or trim the plant.

– Isolate the Plant

The infestation will worsen by using contaminated potting soil, leaving the plants outside in warm weather, or reusing a dirty pot. This is why when you bring it home you must first examine the plant, and isolate it for a couple of weeks so that no neighboring plant will be bothered as well.

Scale on your indoor plants can appear seemingly out of nowhere, and this is why immature scale and scale eggs can also hide in the potting media, and they will grow afterward. In short, if you see that nothing is wrong, you still have to keep it away, for two weeks because these pests can mature.

If you leave your orchid in the old potting media, there is a chance that as the eggs hatch and immature scale grow to become adults, your orchid will be “reinfected” with scale. As a result, you should isolate the plant and make sure to get rid of the pests in different ways, and one of the ways is to spray some water on them and let them drain.

The key to treating malnutrition in plants is knowing what your plant needs. Take time to research aspects like growth habitat, what they prefer, and what they do not like. Always check for the soil first, because there is likely a misalignment in the pH level because when it spikes, it can accelerate. To help you conclude, take various soil samples and get them tested to know the root cause.

– Rubbing Alcohol or Neem Oil

Rubbing alcohol or isopropyl alcohol seventy percent is one of the effective ways to deal with scale pests. It can be used to treat some of the more common orchid pests. It is relatively inexpensive.

This method is effective at removing the adult scales, which is why you can use some rubbing alcohol at least once weekly until the scales are completely gone. It can damage plant tissue if used too frequently. In this case, making sure that you are using it in small amounts to deal with minor pest infestations is fine.

Rubbing Alcohol or Neem Oil

The oil derived from the neem tree is a natural and non-toxic product that can prevent scale pests on your orchid. It is extracted from the seeds of the neem tree and is safe to use in your home, this means that it is an organic substance and not a chemical. It suffocates the scale, so they cannot breathe or move. It disrupts the pest’s life cycle, preventing its growth and further reproduction.

The oil should be mixed with water and not used in a concentrated from for best results. It should be used in the morning, and the orchid plant should be kept out of direct sunlight to prevent burning. Avoid using this oil on hot days, because the plant would be in a vulnerable position.

Where possible, tolerate populations of scale insects. Make sure that well-protected and healthy plants can tolerate light populations of these scale pests, so they do not necessarily require control. It can be worth considering replacing heavily infested plants.

– Insecticidal Spray

For a severe and widespread scale infestation, insecticidal sprays containing Malathion, Orthene, diazinon, or carbaryl are an option. If you are reaching for an insecticidal spray, chances are your orchid has a very serious scale infestation.

In this case, bring your orchid outside to do the treatment. Insecticidal sprays are best used in well-ventilated areas, away from children and pets. Before proceeding with the full treatment, test a small section of your orchid first.

Always follow the directions mentioned on the package and dilute it in water before using it. In addition, these products should be used outdoors only. Once the diluted product is ready, pour it into a spray bottle with a fine mist nozzle. Using the insecticidal spray, thoroughly spray your orchid, ensuring you get the underside of the leaves, crevices where the scale may be hiding, and the potting media.

Spray in the morning and out of direct sunlight, and try to avoid watering your plant the same day you apply the insecticidal spray. Keep the orchid in a shaded, cool, and protected location for the rest of the day; make sure that you would allow the plant to dry off fully before returning it at night. If you still see the scale on your orchid, this treatment should be repeated weekly.

You can also use insecticidal soap sprays. When using such a spray, be aware it can damage new or young orchid tissues. In addition, you should keep your orchid out of direct sunlight for several days following application; it will help to prevent burns and sun damage on the orchid leaves. You should also avoid watering your plant the same day you applied the spray.

When you are ready, bring your orchid outdoors to a well-ventilated area; in this case, remember to do this on a cooler day, where daytime heat will not exceed 80 degrees Fahrenheit.

This precaution prevents damage to the leaves from the heat and sun. Spray the orchid down with this soap solution thoroughly, and ensure that you would do it until it is saturated, nearly dripping with the insecticidal soap spray, and now. Repeat it every few days until the scale is gone.

– Repotting and Trimming

Mechanically removing scale insects may be practical in certain situations, such as small infestations on houseplants or small trees and shrubs. Heavily infested stems can be pruned out and discarded to reduce scale populations.

After removing all the visible scales you found, repotting your orchid into fresh potting media is a good idea. If you have had a large-scale infestation, there may be scale amongst the orchid roots.

By repotting the orchid into new orchid potting media, you will be able to ensure that you have gotten rid of the scale eggs and immature scale hiding in the bark of the orchid. For good measure, you must make sure that you rinse out the roots during the repotting process and get rid of any old bark, which is dependent on roots.

Repotting and Trimming

When repotting your orchid, a new or sterilized pot should be used, and ensure to rinse the roots right. Only reuse the old pot after sterilizing and cleaning it. The whole purpose of doing all this is to ensure you get rid of all the orchid scales, including the eggs and immature scales.

Reusing the same old pot without sterilizing it can reinfect your orchid and defeat the purpose. Insecticide applications are the last choice when mechanical controls and natural enemies are insufficient to prevent plant injury.

There are three chemical control strategies for treating infested shrubs: apply a contact insecticide in summer when the crawlers are active, spray dormant oil before bud break, or use a systemic insecticide.


Understanding why your orchids have scale orchids is easy now that you have gone through our article, and you have even learned how to solve the issue! But before you leave, let’s quickly sum up the main points so that you can help your orchids:

  • Always check for infestations before bringing a new plant home.
  • Getting rid of the damaged parts of the plant is a good way to stop the infestation from spreading further.
  • Apply insecticides whenever you repot your orchids to control the infestation at the initial stages.
  • You can use your liquid soap as a preventive measure. Mix a teaspoon of it in a gallon of water and spray the plant thoroughly.
  • The oil obtained from the neem tree is a natural spray and is the most effective in controlling scales.

After reading our advice here, you can certainly go a long way in tending to your orchids and helping them produce fresh blooms and keep the scales far at bay!

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