Hello. I have scale on my christmas cactus.
I have already treated it once with Bayer Advanced Rose & Flower Care Systemic treatment, plus sprayed a mild mixture of blue Dawn and water.
Both treatments were a couple of weeks ago. I still see some spots of scale.
Not sure if they are dead or not...they are still white, including the smaller specks and the crusty spots.
Now, I have been told to put murphy's oil soap on the plant and wipe off. Do you know if this remedy works, or can you offer any help? I currently have my cactus quarantined from other likely victims.
Hi Christy, scale is a beast to get rid of. It's important to not give up, because they can hide in the tiniest places and reappear when you turn your back.
I've never used Murphy's Oil Soap, but I see no reason why it wouldn't work; it's very mild, and contains the two things I find work very well on scale; oil, and soap.
Anything that smothers the adults (the scale) will eventually kill them off, also keep in mind that the juveniles, called crawlers, are mobile, so even if you treat one area of the plant, it's important to keep going over the same place to ensure that you get them all.
To lower the population, you can also scrape off any adults; I use a toothpick so you can get into the leaf axils and other confined spaces without damaging the plant.
Best of luck with this pernicious creature,
Join in and write your own page! It's easy to do. How? Simply click here to return to Ask the Horticulturist.