---
title: "My philodendron developed these black and yellow patches almost…"
description: "My philodendron developed these black and yellow patches almost overnight. Any ideas what it is and what I should do to treat it? I watered it three days ago…"
url: "https://getplanta.com/community/lKxUkhzRR_aIJD7o1QvtwQ/r-nbeI0VQYWt-GgHf3fpLg?language=ja"
community: "Pests, diseases and problems"
author: "Mark D"
published: "2024-04-30T22:45:07.471247Z"
language: "en"
image: "https://images.getplanta.com/v1/resize/OYCclxd3ZdoBo82kolqAeiqpVwlWMGFGARUt8kud8xc/BYuJXIR5TUi5fh1YdYSO3A.webp?size=large"
---

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# My philodendron developed these black and yellow patches almost…

_Mark Dさんが2024-04-30に投稿しました_

My philodendron developed these black and yellow patches almost overnight. Any ideas what it is and what I should do to treat it? I watered it three days ago and misted the leaves today.

![3件中1件目の添付ファイル](https://images.getplanta.com/v1/resize/OYCclxd3ZdoBo82kolqAeiqpVwlWMGFGARUt8kud8xc/BYuJXIR5TUi5fh1YdYSO3A.webp?size=large)

![3件中2件目の添付ファイル](https://images.getplanta.com/v1/resize/OYCclxd3ZdoBo82kolqAeiqpVwlWMGFGARUt8kud8xc/XztuwKxFS9GTuR-wPH1dVw.webp?size=large)

![3件中3件目の添付ファイル](https://images.getplanta.com/v1/resize/OYCclxd3ZdoBo82kolqAeiqpVwlWMGFGARUt8kud8xc/fuY5dACbRoiVPyP3_yuAww.webp?size=large)

## 5件のコメント

### Sunnyさんが2024-05-01にコメントしました

Looks like Bacterial (or fungal) leaf spot infection which creates yellow circles with black centers that spread. Both can grow with too high humidity, low air circulation and misting. All three keeps water on the leaves too long. Misting and high humidity environments promote bacterial/fungal growth.

I recommend:  
\- Stop misting. Use a humidifier when the plant needs more moisture.  
\- isolate the plant  
\- cut off the infected leaves (use gloves)  
\- disinfect hands/tools🍀🪴

#### Mark Dさんが2024-05-01に返信しました

Thank you! I was probably a bit aggressive is the amount of misting I did more recently.

#### Sunnyさんが2024-05-01に返信しました

I never mist unless I’m trying to mist seedlings or propagate succulent leaves. My average relative humidity this time of year is 85 percent. It’s about 65 percent inside. So, I run a ceiling fan 24 hours a day in the rooms with my plants.

#### Mark Dさんが2024-05-01に返信しました

I live in Southern California and the humidity is low.

#### Sunnyさんが2024-05-01に返信しました

Then, it’s probably just misting and not high humidity causing the bacterial/fungal growth.

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