Plants grown in containers may be completely submerged for 3-24 hours in water with very slight amounts of detergent added, just enough to create a very small amount of bubbles when agitated. This drowns mealybugs, scale and their eggs. It needs to be done at an appropriate time of the year for the plant, and the duration must be chosen carefully. It is more effective if, part-way through the dunk, you physically remove as many insects as you can with a cloth or brush. Immerse the whole plant in the pot; this also kills insects on the roots. I do this with most purchased cacti and succulents, which almost always arrive with mealy bugs and/or scale Plants with high levels of infestation will have many small insect piercings though which detergent may enter and cause tissue necrosis. A heavily infested plant would be better treated with several 1-hour dips at weekly intervals than one long dip. Leafy plants tolerate less submersion than non-leafy plants, and multiple shorter immersions are probably better for them than one long stretch. During warm weather most cactus without severe infestation easily tolerate a 24-hour submersion. I let them dry completely before watering again. Leo Martin Phoenix Arizona USA Zone 9? Sent with [ProtonMail](https://protonmail.com/) Secure Email. _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/…