3 Homemade Insecticidal Soap Sprays for Plants

You’ve spent weeks carefully tending to your garden, and now aphids and other sap-sucking pests have appeared on your plants. Before spending money on commercial products, try a homemade insecticidal soap spray instead.

It’s a natural, organic option for controlling small, soft-bodied plant pests. Moreover, soap spray insecticides are gentle, safe, and highly effective.

Best of all, you can feel good about avoiding harsh pesticides while still protecting your garden.

What is Insecticidal Soap?

The remedy is a natural pest control method that uses potassium salts of fatty acids to kill small, soft-bodied insects and related pests.

The soap suffocates the pests by clogging their breathing holes and damaging their cell membranes. It works on contact, so you must spray the critters directly to be effective.

The good news is that it is non-toxic to humans and breaks down quickly in the environment.

How Does It Work?

It works by penetrating the insect’s exoskeleton and disrupting cellular membranes. The soap’s fatty acids break down the insects’ protective wax and oil coatings, causing them to dehydrate and die.

It works on contact alone, so repeated applications may be needed. Soapy water also helps to remove the scent of ant pheromones.

How to Make Natural Insecticidal Soaps

Below are two simple recipes for insecticidal soap that you can use in your garden and home.

They make great homemade bug spray for your plants. You can also use it on hard surfaces, like killing ants on the floor or kitchen counters.

Recipe One

To make a natural plant insecticidal soap at home, you will need organic liquid soap, pure water, and vegetable oil.

Use a mild dish soap, preferably one with a natural, eco-friendly formula that is free of dyes and fragrances. Castile soap made from plant-based oils works well.

Any organic cooking oil will work, such as canola, soybean, or cottonseed oil. However, olive oil should be avoided, as it can block the pores of the leaves [1].

To make the spray:

1. Mix 2.5 tablespoons of organic liquid soap and 2.5 tablespoons of vegetable oil. Shake or stir well to combine.
2. Add the mixture to 1 gallon (3.79 L) of water. Shake or stir again to thoroughly mix it.
3. Next, pour it into a spray bottle and label it clearly. Shake it before each use.
4. Finally, thoroughly spray the leaves of your plants, especially the undersides.

This natural, DIY insecticide is a safe and organic option for controlling many common soft-bodied garden pests. But be sure to spot-test a few leaves first to check for any damage before spraying the entire plant.

Recipe Two

For this recipe, you will need just two ingredients:

• 4 tablespoons of organic liquid soap (some people use Dawn dish soap, but we prefer not to use it).

• 1 gallon (3.79 L) of water

Mix the soap and water thoroughly in a spray bottle or pump sprayer. Shake before each use to combine.

That’s it! The soap will naturally repel soft-bodied insects, such as aphids, spider mites, mealybugs, and whiteflies.

It’s also a mild liquid soap spray for your plants. However, test it on a leaf first to check for leaf burn (some plants are very delicate); then spray your plants thoroughly.

This gentle, non-toxic spray is effective for both indoor houseplants and outdoor gardens.

Recipe Three

This one has castile soap, neem oil, and water.

To make a DIY insecticide, mix one tablespoon of neem oil with one tablespoon of organic castile soap in a liter of water. Dr. Bronner’s liquid castile soap is a good brand.

Shake well and apply it to your plants, as in the other recipes.

How to Use Soap Sprays

Once your insecticidal soap spray is mixed, it’s time to use it. Apply it when insects or their damage are first noticed.

For optimal results, spray plants in the evening or on overcast days when the sun’s intensity is reduced. The direct sun can burn wet leaves, even with a gentle soap spray.

Spray the pests directly. Also, thoroughly coat the tops, undersides, and stems of the leaves.

Additionally, pay close attention to areas where you see insects or insect damage. Spray until the plant is thoroughly wet, allowing it to drip for maximum coverage.

This solution targets mature insects, larvae, and nymphs, but does not harm tough eggs.

How Often to Use

To keep your plants pest-free, it’s best to spray them regularly with homemade insecticidal soap.

As a general rule of thumb, spray every 14 days as a preventative measure. More frequent spraying, approximately every 4 days, may be necessary if you’re trying to eliminate an active infestation.

During the peak growing season, from spring to summer, spraying once a week or every other week is a good idea. Doing so will help deter common garden pests.

Types of Insects and Related Pests That Insecticidal Soap Controls

Insecticidal soap spray controls several common plant pests [2]. The soap solution is most effective against:

• Aphids
• Sawfly larvae (rose and pear slugs)
• Mealybugs
• Mites (spider mites, broad mites, rust mites, etc.)
• Young scale
• Leafhoppers
• Whiteflies
• Psyllids
• Thrips
• Leaf miners
• Ants
• Earwigs

Commercial Products

If you prefer not to make insecticidal soap, you can purchase popular options that many gardeners trust.

Below are two good options:

Bonide Brand

This ready-to-use insecticidal soap can be applied indoors and outdoors to kill insects on contact. It is powered only by potassium fatty acids (derived from plants).

Bonide Insecticidal RTU Soap also does not remain in the environment. You can apply it to your crops as often as desired (weekly or bi-weekly).

You can also apply it to edible plants up until harvest day.

Monterey Brand

Monterey Insecticidal Soap is an all-natural product. It acts as both an insecticide and a fungicide.

This soap spray helps control common pests and diseases in your garden. It works on contact, so spray when insects are most active for the best results.

It also helps to prevent and control powdery mildew.

Takeaway

The above are our insecticidal soap spray recipes, which can help you combat common garden pests without using harsh chemicals.

The best part is that you can feel confident knowing what’s in the spray and that it’s safe for the environment, kids, and pets. So grab your spray bottle and get mixing; your garden will thank you.