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Homemade Soap as Insecticide?

 
Brandon Greer
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Location: 1 Hour Northeast Of Dallas
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I've read that soap is an insecticide but is homemade soap made from just lye and fat an effective insecticide too?
 
Charli Wilson
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Location: Derbyshire, UK
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Soap is usually considered an insecticide because it causes insects to dry out- and so they die. So any soap would do this, hand made or not.
 
Brandon Greer
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Charli Wilson wrote:Soap is usually considered an insecticide because it causes insects to dry out- and so they die. So any soap would do this, hand made or not.


Just curious: What is it about the soap that dries them out? Is it the lye? And if so, would a soap with a greater amount of lye be even more effective?
 
Charli Wilson
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Soap causes oils and fats to break up, so causes the wax on the insects skin to dissolve- and so they dehydrate and die- it only really works on soft-bodied insects (like aphids, whilst things like ladybugs seem to be unaffected), and it only works whilst the soap is wet (once dry it becomes harmless). Afraid I don't know if a lye-heavy soap would be any better than regular soap (my knowledge of chemistry doesn't stretch quite that far!). People claim that adding various essential oils to their soap makes it a better insecticidal soap (I think things like tee-tree are meant to hang around on the plant and further repel insects, and some essential oils are considered insecticidal).

I just spray washing up liquid at my aphids... I've never actually tried the essential oils thing!
 
Brandon Greer
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Charli Wilson wrote:Soap causes oils and fats to break up, so causes the wax on the insects skin to dissolve- and so they dehydrate and die- it only really works on soft-bodied insects (like aphids, whilst things like ladybugs seem to be unaffected), and it only works whilst the soap is wet (once dry it becomes harmless). Afraid I don't know if a lye-heavy soap would be any better than regular soap (my knowledge of chemistry doesn't stretch quite that far!). People claim that adding various essential oils to their soap makes it a better insecticidal soap (I think things like tee-tree are meant to hang around on the plant and further repel insects, and some essential oils are considered insecticidal).

I just spray washing up liquid at my aphids... I've never actually tried the essential oils thing!


I'm using some soft soap (store bought) in a mix with onions, garlic and peppers and it's working great. Wish I would have known about it last year when my garden was pillaged and decimated. Now, that I see it works, I want to make my own soap so I don't have to wonder what chemicals are going on my plants. Anyways, thanks for the info. Good stuff to know!
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