It’s an unfortunate fact of orchid ownership: Pests happen. However, a pest infestation doesn’t have to spell disaster for your orchid; with the right awareness and treatment, pests can be quickly dealt with and your orchid can go on to live a long life.
One of the most common Phalaenopsis orchid pests are scale. While there are currently 27 different identified species of scale, the most common experienced by orchid owners in the United States is brown scale. Characterized by yellow or brown oval “shells” that can appear on all parts of the plant, scale can be fatal to an orchid if left untreated.
How to Recognize Scale
In the early stages, scale can be difficult to see because the crawlers—also called immatures—are very small and yellowish in color. As scale matures, it grows larger and takes on more of a brown color. The damaging effects of scale are most easily contained when the infestation is caught early.
How Scale Infests Your Plant
The most common way orchid owners find themselves with a scale infestation is by purchasing an infested plant. If an infested plant then comes in contact with a healthy plant, crawlers can move from plant to plant. Crawlers can also be transmitted when blown from plant to plant, which is common for orchids left outdoors.
Infestations can spread very quickly, so the first step in treating an infected orchid is to immediately isolate it from the rest of your plants. Then, you can follow the treatment plans outlined below.
How to Treat Scale
If your orchid’s scale infestation isn’t too extensive, you can potentially manage the damage with simple household products you likely already have on hand or are easily found in the store. But if the infestation is severe, the use of insecticides might be necessary.
Here are a few treatment options you can try:
- Rubbing alcohol: Administer either with a cotton ball or a misting bottle (50/50 water and alcohol solution), isopropyl alcohol can help you to get rid of scale infestations, but will need to be repeated every one to two weeks.
- Repotting: Your orchid’s potting medium can harbor scale eggs and crawlers, so repotting is one way to minimize the chances the scale infestation will continue.
- Horticultural, neem and mineral oils: These oils smother insects and are considered a safer option for orchid owners with pets or children. Mix the oil with water and completely cover the plant with the solution via a spray bottle.
- Insecticidal soaps: One step down from an insecticide, insecticidal soaps can also help manage infestations, but make sure to keep your plant out of the sun after application to avoid sunburn.
- Insecticides: Since these are harsh chemicals, look for a synthetic option like Orthene, Malathion, Diazinon or Carbaryl.
Dealing with a scale infestation requires patience, diligence and consistency, but with the right process and attitude, you can return your orchid to health and say goodbye to scale.