Herbal Insecticidal Soap for Indoor Plants

Houseplants brighten the appearance of any room.

The thoughtful placement of houseplants can liven up any decor. However, just like the foliage found outdoors in the garden, indoor plants are vulnerable to infestation by insects and pests. While there are many commercial products that can be used to help fight off an insect attack, many insecticidal treatments contain toxic chemicals that may make them unsuitable for use indoors. A safer alternative can be found in a basic herbal soap spray that can easily be made at home. Not only does it kill bugs on contact, it is nontoxic and easy to apply.

Things You'll Need

• 2 tbsp. mild liquid dishwashing soap
• 1 cup herbs
• Coffee filter
• Plastic spray bottle

Instructions

1. Pour 1 qt. of water into a large bowl. Add 2 tbsp. of mild liquid dishwashing soap to the water and stir gently. Use liquid soap, not dry powder; the powder is too harsh for use on plants.

2. Gather your herbs. Many herbs naturally repel insects due to their pungent aroma. Select one or more strong smelling herbs to add to your soap solution. Garlic, basil, chives, pennyroyal, chamomile, red pepper, mint, sage, coriander, lavender, rosemary and tansy can all be used to help keep insects at bay.

3. Place up to 1 cup of dried or fresh herbs into a shallow dish. Pour 2 cups of boiling water slowly over the herbs. Wait for the water to come to room temperature, then pour the resulting brew through a coffee filter to remove any solids. Add the liquid to the soap solution and stir gently to incorporate the infusion.

4. Transfer the solution to a plastic spray bottle. Spray a small portion of the plant prior to making a more general application. Visually inspect the plant for two to three days, checking for any signs of negative reaction to the soap spray. If no reaction occurs, apply the spray to the entire plant, evenly covering the foliage. Spray any visible insects, thoroughly coating them with soap. Treat the undersides of the leaves as well as the tops.

5. Repeat the application process every four to seven days until the insect situation has been completely resolved.

References

• Care 2: Homemade Insecticidal Soap
• Fine Gardening: 35 Pest and Disease Remedies
• Colorado State University Extension: Insect Control - Soaps and Detergents
• Colorado State University Extension: Managing Houseplant Pests

Resources

• Home Herbal Gardening: Make Your Own Herbal Insecticidal Sprays