Homemade Insecticidal Soap Spray
1 T. Ivory Soap (grated with a cheese grater**)
1 t. vegetable oil
1 quart water
Mix together and use a hand sprayer to spray on affected plants.
I was recently asked what soap recipe I use on my plants, since I don’t like using chemicals. This is a recipe that I got from talking to my local County Extension office, mixed with information I got off the internet a long time ago and sorry, I can’t remember the original source(s). I just got a cheap hand pump sprayer from the Home Depot for around $10.00 and wrote “Soap Spray Only” on it with a permanent marker so my hubby wouldn’t use it for something toxic. 🙂 You definitely need to use a soap like Ivory (I have also heard you can use a Castile Soap as well). Most commercial soaps are actually detergents rather than true soaps and contain different chemicals. I know Ivory is listed as a true soap. You may need to check around if you choose to use another brand.
The oil is important as it helps the spray adhere to the bugs you are trying to kill. I have used this with success on my raspberry plants when they were in flower and my peach tree, but if you are concerned about plant damage I would test a small area first. Some plants are more sensitive to damage from soaps than others . I have sprayed once a day for several days in a row (on my peach trees infested with aphids) and not had any problems, but I have often heard that you should repeat applications every 4 or 5 days. If in doubt, test your plant first.
If you mix a batch of this in advance, it will become very gelatinous. You may need to thin it a little bit to get it to spray correctly out of the sprayer.
Another thing to remember is that this will not cure your bug problem. It will only reduce the numbers. The spray has to hit the bugs to destroy them and it does this through dessication (drying them out, like food grade diatomaceous earth). This spray will kill beneficial bugs too, so be careful when you spray that you are not killing beneficial ladybugs or bumblebees at the same time.
**As an added bonus, you can mix a fun kid’s activity in here. Ivory Soap is especially easy to carve. My children have really enjoyed trying to carve a bar of soap into things like boats, animals, etc. and then you can just use the shavings for your soap spray without having to grate any, your children can use their carving for their next bath and your whole house will smell clean and soapy for a couple of hours. It is a pretty strong fragrance so be aware of that.