Insecticidal Soap is the organic insecticide of choice for many soft-bodied garden pests. Here’s the deal on this product.
This kind of soap is a highly refined soap (potassium salts of fatty acids if you want to be specific)
Is it different than household soap?
Insecticidal soap is formulated to destroy the protective coatings of insects so it is made a little differently.
But you can mix household soap at a ratio of 1 part of soap to 40 parts of water for an effective spray.
Be careful in that some plants will not appreciate this mix and you could damage them. Test a few leaves (and flowers) before you spray the entire plant. Spray and wait 24-48 hours to see if there is any damage.
Won’t household soap work?
Yes, it will. But be aware that it will not have the same consistent effect as the insecticidal soap will have.
It will also damage some flowers or leaves much faster than the organic soap made for the purpose.
What about dishwashing soap – will that work?
Yes, it will work but it’s not usually soap – it’s usually detergent.
And it’s harder on plants than the household soap.
Do be careful if you decide to mix your own. I’ve handled more than one upset gardener because they stripped the protective surface from their favorite plant leaves.
What Do You Use?
I have used Safer’s insecticidal soap for years – both in the greenhouses, my house, and garden. I’m a big fan and here’s why.
- It’s all listed in OMRI (Organic Materials Registration Institute) so there’s nothing in there that’s a problem.
- It smells clean – has no earthy or unpleasant smell to it. Heck, your plants smell like they’ve had a shower.
- It kills a ton of soft-bodied pests including Aphids, Earwigs, Grasshoppers, Harlequin Bugs, Leafhoppers, Mealybugs, Mites, Plant Bugs, Psyllids, Sawfly Larvae, Soft Scale, Spider Mites, Blossom Thrips, and Whitefly.
- You can use it on almost everything including Roses, Flowers, Fruits, Vegetables, Houseplants, Trees, Shrubs and Ornamentals.
- Do not use any insecticidal soap on Euphorbias, Gardenias, or Delicate Ferns (you’ll regret it if you do – they can go an “interesting” shade of dead, brown foliage)
Ratio to Mix
The standard mix ratio is 40 parts of water to 1 part of soap.
Having said that, there’s no way to standardize this with household soaps and detergents so you’re going to have to experiment to ensure you get a good kill but no leaf or flower burning.