White powder like substance at base of Christmas cactus


After the heavy rain in Toronto last week 2 of my Christmas cactus have developed a white powdery residue at their base… the dishes they were in as well.
Don’t know what to do and whether this will affect the plants long term. Look forward to help


While schlumbergera bridgesii , Christmas cactus, may enjoy sheltered outdoor site for the summer, it is a succulent. Dry conditions on the plant and in the soil are essential to survival.

Powdery mildew likes the same type of habitat that succulents like: warm, relatively dry areas. Because succulents and powdery mildew thrive in similar living conditions, succulents are the most infected types of plants, according to the University of Rhode Island Green Share website. Your infection may just look like the classic white, powdery coating. It can also take on a gray appearance with round yellow, brown or black growths. The mildew can appear in just one spot, but more commonly, it spreads to other leaves, stems and buds of your plant. So you need to clean the plant material thoroughly; you may use insecticidal soap safely and legally. Consider repotting as well, or at least scrub the dishes inside and out.

You may also like to see the information from another source:

http://forums.botanicalgarden.ubc.ca/christmas cactus