Shop Products
Houzz Logo Print
drewstoddard

White chalk-like fungus/substance on plants

DrewStoddard
10 years ago

I need help identifying a white chalk-like fungus or substance of some kind that consistently seems to plague certain plants that I grow in my house. As the attached photo shows, the two palm plants are the worst affected, and they can become almost completely covered if I don't wash this chalky white substance off every couple of weeks. It does not seem to harm the plants much, and it reproduces very fast. Some plants seem to be unaffected, but I can't tell whether it's because of their position or their species.

I have tried spraying with two different kinds of commercial Fungiside (Safer Brand and Garden Safe) but neither seemed to have any effect.

Can anyone help me identify what this substance is, and how I can get rid of it?

Comments (17)

  • DrewStoddard
    Original Author
    10 years ago

    Thank you for your very helpful response. The spots do not seem to move, but your suggestion of mealy bugs seems to be the best answer anyone has come up with so far. The way the white substance spreads does seem to indicate insect behavior. I will try an insecticide and see if that works.

    On the broader subject of tap water poisoning, this is the first time I have heard of this and it is extremely useful. Several of my plants look as though they are becoming sick, and this happens after I water them with tap water for about 4-6 months. I am going to start watering them with spring water which I have delivered for drinking. I don't know if it's a pure as rainwater but at least it will be different and it will be interesting to see if there is a change.

    Thanks again for all of the helpful information. I really do appreciate the time and effort. :)

  • Tiffany, purpleinopp Z8b Opp, AL
    10 years ago

    You're welcome. HTH! Don't forget the dripping out is as important as the water (or what may or may not be in it.) Going outside in the shade to enjoy the summer humidity might be appreciated by the plants also. Sending good vibes!

  • Laura Forero
    7 years ago

    Has the problem been solved? I have a very similar problem on a Strombili plant. I am sure it is not a fungus because it doesn't have a hyphal mass or any hyphal growth in general. Rather, they are small rod like structures. Like white rice.

  • rhizo_1 (North AL) zone 7
    7 years ago

    Laura, I suggest that you start a new thread rather than piggy-backing on someone else's. Pictures will certainly help you get an accurate diagnosis.

  • Diane Romanov
    6 years ago

    Thank you for posting this question and Tiffany for the answer! Very helpful!!

  • Andrea ME z5b
    6 years ago

    @Tiffany, what do you mean by "tap water poisoning"?

  • Tiffany, purpleinopp Z8b Opp, AL
    6 years ago

    Chlorosis from over-exposure to lime, chlorination, fluoride, anything else in water that might make a plant ill &/or alter the PH of the soil.

  • ian_elder001
    5 years ago

    Can anyone tell me what this chalk / rice like substance on my palm plant and how to get rid of it? Thanks

  • Tiffany, purpleinopp Z8b Opp, AL
    5 years ago

    Ian, your plant has some kind of bugs, I can't see them clearly enough to see exactly what they might be.

  • Luis Godinho
    5 years ago
    last modified: 5 years ago


    Doesn't

  • HU-504933735
    5 years ago

    Drew my palm looks the exact same as your first pic. Were you able to fix the problem? If so what worked?

  • Dollie Jacinto
    4 years ago
    last modified: 4 years ago

    I once had this problem until I started spraying with dawn dish soap and water. Seems to work. Inspect them every couple of days or so and spray generously until gone. It takes work but worth the effort. You should also cut off the infected branches and spray where the growth (closer to roots) starts. This is the area where these bugs live or colonize (so to speak).

  • gardengal48 (PNW Z8/9)
    4 years ago

    Ian's problem is also mealy bugs but Luis' is showing a scale infestation. Different control strategy required for that but easily researched. Horticultural oil is usually the go-to for scale.

  • Kathy Smith
    4 years ago
    last modified: 4 years ago


    Mine is similar to the first pic, attaching here? Is it a bug also?

  • Michael Mccabe
    2 years ago


    Help, what is it and what do I do? It's my first palm.

  • ken_adrian Adrian MI cold Z5
    2 years ago

    the entire point of pulling up an old thread.. is to read the thread for the answer ... its all up there ... palm smack to forehead ....