Can anyone help me identify the mold growing in two of my potted plants, and how to treat them?

I bought the plants and potted them two weeks ago. The flowering plant is in a pot with a drainage hole at the bottom, and the succulent is in a glass jar with no drainage. Neither has any substrate gravel in the bottom. We used a combination of the two potting materials pictured below - "Miraclegrow indoor potting mix" and "Ecoscraps fresh start plant food".However, we did not clear away majority of the original soil around the roots of plants when we bought them.

The flowering plant suggest watering twice a week.

They sit in a glassed-in vestibule that gets lots of sunlight during the day (windows on the east and south side, and a clear ceiling). I moved them outside yesterday when I noticed the mold.

UPDATE: After moving the plants outside, the mold receded! Thank you SE for the analysis and help.

  • 1
    That was quick! I didn't realize you were right here! The edits are my pleasure. I'm glad they were okay with you. Of course you know how to roll back if not. I have some mold in my plants too, so I'm glad you asked this. I'm looking forward to the answers! Jul 2, 2017 at 18:25
  • After putting the plants outside and in the sun the mold receded significantly. Thanks for the answer. Oct 16, 2018 at 20:26
  • That's great news!! You might want to edit that as a follow-up in your question so people would know what worked for you! Oct 16, 2018 at 22:58

1 Answer 1


This is a simple 'gray mold' that is absolutely not harmful. Rake the top of the soil and it should go away.

What I am worried about is your watering practices. This fungus needs constant moisture and/or little ventilation to grow. Are these pots filled with potting soil or did you add garden soil or 'compost'? Do these pots have drain holes? Did you put gravel or rock beneath the soil and above hopefully, the drain holes? How often do you water?

Reduce watering, rake the top of this soil and prune out dead leaves/remove any organic debris. Depending on where you live and where these plants live (indoors or out of doors) you should put a fan on them to help push away air and moisture and O2. Have you fertilized? That clear bowl probably has no drain holes, correct?

Please give more information about your soil, drainage holes, layer of rock/gravel at the bottom, how often you water, are these pots in the sun or are they under a roof on the patio or are in the home? Guess after reading that they are in a glassed in vestibule or sort of greenhouse. Yes, you need to get a fan going in that room and possibly some shade cloth to reduce the sunlight when it gets too hot.

You essentially have a 'green house' and with that there are management skills to learn. Ventilation, watering, potting soil, fertilizer...great question. A bit more information from you. This mold was just a little wake up call is all...grins.

  • Thank you stormy. The glass pot does not have any drainage hole, and the other pot does. I will post the rest of the information later tonight. Thanks and I look forward to any additional help you can offer. Jul 2, 2017 at 19:36
  • Great. To have a 'glass' vestibule is priceless in a home but there are things that need to be considered to be able to use it to the maximum. If you can find the soil bag or fertilizer bag/bottle please add that information as well.
    – stormy
    Jul 2, 2017 at 19:42
  • I have updated the OP to add the information you asked about. Please let me know if there is anything else that might be helpful to know. Any other insights would be great. Thanks again. Jul 3, 2017 at 14:36

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