Did you know there's a simple way to make soft soap much more effective against plant pests? In this post, I'll show you how.
The Secret to Soft Soap's Power
The trick is understanding how soft soap works. It is a type of potassium soap that dissolves easily in water. When you spray it on a pest—like an aphid or a spider mite—it creates a film around the insect and suffocates it.
The problem? It only works as long as the soap film remains wet. If you apply soft soap on a hot, dry day, the water evaporates in a couple of minutes. The pest might be suffocated for a brief moment, but then it can breathe again, and the treatment fails. The soap might have washed away the honeydew, but it didn't kill the pest.
To get the full insecticidal effect, you need to keep the soap film wet on the plant for a longer period.
My Method for Maximum Effectiveness
- Treat on a humid day: If you have the right weather conditions, apply the soap on a humid day. Not a rainy day, because rain would wash the soap away, but a day with high humidity will keep the soap film wet much longer, giving it more time to suffocate the pests. You'll be amazed at how much more effective it is.
- Keep spraying: If you have to treat your plants on a dry day, you can apply the soap and then spray shortly after with water to prevent it from drying out. The treatment becomes something like soap-water-water-soap-water. I've found this method works wonders.
Here is how I do it:
- First, prepare your soft soap solution as directed.
- Spray your plant thoroughly, making sure to hit the undersides of leaves where pests often hide.
- Wait a minute or two, and as the plant starts to dry, spray a light mist of water to keep the soap film wet. Don't spray so much that the soap drips off.
- Once the plant starts drying again, spray the soft soap solution one more time.
- Repeat this process a couple of times. By keeping the plant wet for about 15 minutes, you can drastically increase the soap's effectiveness.
After this treatment (a day later), you can use neem oil or other insecticides. Their effectiveness will be much higher because the pests' protective cuticle and honeydew will have been weakened.
Happy gardening!
