SOAP verses DETERGENT

Insecticidal soap is a frequently recommended pesticide for use against many soft-bodied pests that affect the garden and landscape. It has no residual effect and is considered safe for humans, pets, and most beneficial insects.

I see many posts on some gardening Facebook pages that give recipes for homemade insecticidal soap using common dish soaps.  Unfortunately, many recipes aren’t for insecticidal soap at all, they are for insecticidal detergents since most dish “soaps” are detergents.

There is a big difference between soaps and detergents and how they affect our plants.  A soap has long and short chain fatty acids, and it is the fatty acids that work against most soft-bodied insect pests. True insecticidal soaps only have the long-chain fatty acids.  Detergents are mostly petroleum based synthetic chemicals that are designed to breakup oils and grease.  That’s what makes a detergent superior to a soap for cleaning dishes.  However, that property of a detergent is what makes it bad for plants.  Detergents can remove the natural protective oils on plant leaves and make the plant more susceptible to pests and diseases.  The soap that has been studied and approved for its ability to safely control soft bodied insects in the garden is made from the long chain fatty acids of potassium salts.  There are numerous products that are commercially available either as a concentrate or a ready to use spray, and these are all properly labeled for pesticide use.

The main thing is for you to be aware of what you are spraying on your plants and keep the Dawn under the kitchen sink where it belongs.

Here are some links to informative information about insecticidal soap:

https://www.gardenfundamentals.com/insecticidal-soap-use.../

https://www.gardenmyths.com/dish-soap-damage-your-plants/

https://hgic.clemson.edu/.../insecticidal-soaps-for.../

OhioGardener wrote:Dawn Detergent is anti-bacterial.  We want the microbes in our gardens, so we don't want to use anti-bacterial soap.

The peppermint scent of Dr. Bonner's Castile Peppermint Soap has the added benefit of repelling many insects. So, in addition to the soap controlling the pests, the peppermint repels other insects.