Liquid soap Insecticides Solved

[Peter C]

Can anybody tell me what liquid soap to use so as I can make up an organic Insecticide - Fungicide, I have been reading a book by David E Wright called Stuck on Cactus giving the name Ivory as a type, this is an American publication so am unsure if this is available in the UK
Can anybody give me any advice?

[iann]

The closest UK equivalent would be Fairy Liquid.

[Peter C]

Hi Ian,
Thanks for your help; will Fairy be suitable as it specifies non detergent type soap?

[Julie]

Or Ecover washing up liquid, to keep it green? I think all that's needed is a surfactant. How about boiling up some of Lakeland's soapnuts (for laundry)? It foams in the machine but as a liquid soap it's not very foamy (compared to the laureth/lauryl suphate family) but it's foamier than the filtrate from boiling up your soapwort leaves.

Maybe add a bit of Neem?

Wonder if Tea Tree oil would work, or be damaging to the plant. It's antiviral, antibacterial and antifungal, don't know about larger critters. Has anyone tested it on a not so dear plant?

End greeny lecture.

[Derek]

I have found Fairy washing up liquid to be perfectly adequate for drowning red spider mites after years of unsuccessful attempts with proprietary insecticides, some of which have probably done me more harm than the pests! However I have to stress that the spraying of the infested plants has to continue at intervals of about 10 to 14 days until they are clear of pests as the soap doesn't kill the eggs. I usually find three sprayings to be sufficient. Examination of the plants with a powerful magnifying glass will tell you when the mites are all wiped out.
Regards Derek Milton Keynes UK

[tony_lb]

Speaking as a chemist, what I find amusing is, knowing the chemical processing and raw materials which go into commercial soap, how anyone can class it as 'organic' in the modern as opposed to chemical sense of the term. That's not to say it might be better than many of the alternatives. One nice thing is that, unlike detergent, it is acidic so is less likely to hurt plants which benefit from an acid environment. Detergents on the other hand are alkaline.

Tony

[Phil_SK]

?? Doesn't soap have sodium hydroxide (that's really hard to wash out) left over from saponification?

[iann]

In practice, most soaps will test alkaline. The fatty acid salts that are the key component of soap are not strong acid or alkaline but soap is made using strong alkalis and some of these remain behind. Expect pH 10 from a soap unless it makes explicit claims otherwise. Some are lower (for sensitive sking ), a very few may actually be on the acid side. Alkaline soap is extremely good for removing grease and oil.

Some detergents are also acid. A good example would be good quality detergents intended for washing cars, since alkali detergents will damage expensive wax finishes.

[tony_lb]

Whoops!

Got it the wrong way round! It's been 10 years since I last taught the topic, but I'm disappointed that my memory would go that fast. Caustic soda and fat would obviously give an alkaline product, and the other ingredients don't help either.

Tony

[Phil Hocking]

Have a look at this site. Some of the soaps are not available in the UK but the Dove brand is, and that one is pH 7, i.e. neutral. I believe they market it on that basis. If you were to use it I guess you would grate it and mix with water. If they neutralise it with boric acid you'll be giving your plants boron, which is a required trace element. Too much might be harmful though.



Somerset Phil