Tips On How To Use Insecticidal Soap On Orchids

For a long time, chemical solutions were all the rage when it came to pests, but these turned out to be harmful to beneficial insects and sometimes the plants themselves.

This has led to a rapidly growing interest in organic methods for controlling insect infestations.

insecticidal soap and orchidsPin

When it comes to your orchids, this shift from commercial insecticides can be important, as there’s a much smaller chance of harming these cherished flowering plants.

Insecticidal soap is one method that’s popular these days among orchid growers. But what is an “insect soap,” and how do you treat an infested orchid plant?

How To Use Insecticidal Soap On Orchids

When planning to use any natural remedy on your plants, it’s important to know what they are, what they do, and the potential risks.



Here is what you need to know about insecticide soaps and how to use them in your orchid collection.

What Is Insecticidal Soap?

Insecticide soap is pretty much what it sounds like: a 2% percent soap solution with pesticidal properties.

The most basic recipe is diluted pure liquid soap, such as castile soap, Neem oil is another.

This makes it easy to make at home, although commercial products are sometimes more effective and may include additional ingredients.

When using an insecticidal soap, it’s actually the fatty acids that are the active ingredients contained in the soap itself that can dissolve the waxy coatings on soft-bodied pests.

The Pros of an Insecticidal Soap Solution

Insecticidal soaps are all-natural insecticides and safe on most plants. It’s an effective medium to control soft-bodied insects that consume plant sap and cause leaf damage, such as thrips and aphids.

The purer form leaves behind little to no residue and is fairly effective against many invasive orchid pests, including:

  • Ants
  • Aphids
  • Earwigs
  • Flies
  • Mealybugs
  • Millipedes
  • Mites
  • Scale
  • Spider mites
  • Spiders
  • Thrips
  • Whiteflies

It doesn’t harm birds or hard-bodied insects such as beetles.

The Disadvantages of Insecticidal Soap

Unfortunately, while insecticidal soap is generally harmless to hard-bodied insects, it can still kill their larvae, meaning you may kill lacewings or ladybugs before they mature.

Also, many commercial insecticidal soaps contain vegetable oil or other additives meant to leave behind a residue.

This, at first, sounds like a good idea since the soaps are contact killers, but the residue can interfere with photosynthesis and transpiration and increase the risk of damage from the sun in some cases.

Stressed or underwatered plants are at a higher risk of being damaged by these bug-killing soaps, and wilted leaves can be severely damaged.

Also, keep in mind that this treatment isn’t a one-and-done application. It will need to be applied multiple times. It also only works when the eggs and insects are in direct contact with the solution.

Finally, plants can sometimes be sensitive to soap, resulting in adverse effects. This can extend to individual plants belonging to species or cultivars not normally sensitive to soap sprays.

New growth tends to be more sensitive, as will the orchid flowers themselves.

Using Insecticidal Soap on Your Orchids

While there are certainly some potential problems if you aren’t careful, insecticidal soap is generally considered safe for use on orchids like Phalaenopsis when used properly.

Begin by mixing the soap and adding it to a clean spray bottle. Mix 1 tablespoon of castile soap per quart of water or 5 tablespoons of soap per gallon of water.

Use distilled or filtered water, as hard water can add more residue to the diluted solution. Shake the spray bottle well before use.

You may also use a soap-soaked cotton swab or cotton ball to swipe and remove insects physically you can see on the undersides of leaves and stems. Also, spray the potting medium.

You’ll want to first make a small amount and test it on a single leaf to ensure the plant won’t have a negative reaction.

If there are no reactions in the initial sprays, make a larger batch and treat the entire plant.

The best time for treatment is at either dusk or dawn when beneficial insects are at their least active.

You will also want to avoid applying on days where the temperature is expected to exceed 90° degrees Fahrenheit.

Spray the orchid plant thoroughly, making sure to get the bottoms of leaves, which is where many pests prefer to hide. Make sure to cover all plant surfaces.

As mentioned, avoid spraying wilted leaves, tender new growth, and the flowers themselves.

Once applied, allow the insecticidal soap to sit for 1 to 2 hours.

While the dish soaps dries quickly, this gives it a little more time to affect any pests it made contact with.

Some Final Notes

Insecticidal soap isn’t a perfect solution, as the soap content can damage some parts of your orchid.

On top of that, it’s a contact killer, meaning it’s not overly effective when used on its own. It’s always a good idea to use natural pesticides for orchids at home as the effective eradicator of common orchid pests.

That said, when you have a severe infestation, using insecticidal soap can help to reduce the population just enough to allow stronger methods to take effect and can also be used as a preventative to some degree.

JOIN Our FREE Plant Care Newsletter 

By entering your email address you agree to receive a daily email newsletter from Plant Care Today. We'll respect your privacy and unsubscribe at any time.