Homemade insecticidal soap for plants

To make the insecticidal soap spray, shave one quarter of a bar of Fels-Naptha laundry soap (about 1 inch) into 1 quart of heated water and stir until dissolved. This will be your insecticidal soap concentrate. Put the soap solution into a labeled jar.
To use the soap spray, put 1 teaspoon of concentrate per quart into a sprayer. This insecticidal soap is a contact poison, so spray it directly onto the insects you want to eliminate from your home, garden or orchard. For additional killing power, add one-quarter cup of rubbing alcohol per quart.