Hi everyone,

So I have this monstera for about 1 month now. The problem started by browning the tip of some leaves but it went quick from that to those spots with grayish center, brown borders and yellow hue that seems to me to, be a fungal problem. I don't know which I can be nor how to treat it. More and more the tips and edges of the leaves get more brow. Can someone help me?






[lightbox]2020-05-20/arthurdslopes/b18ba4[/light

It is not a fungal problem.

Is it still in its plastic nursery pot or did you repot it?

How do you decide when to water it and how much do you give it?

How far is it from the nearest window?

Thanks for your reply Will!

So, it's not in its plastic nursery pot anymore, I repoted it 2 to 3 weeks ago and I put it in a higher one (made some holes in a bucket that I had here, put some rocks on the bottom for dreinage and also to take some of the size of the pot) so, actually this big pot is just a little bit bigger than the size of the plants roots.

About the light, it is in my balcony, facing north west, so it gets a lot of bright, bright light. I live in Brazil, close to the beach and for that I have a lot of humidity!

As here I have a problem with fungus gnat I put sand to cover the top of the soil, so I use a toothpick to see the need of water, inserting it into the soil and then seeing if it came out dry or dirty.

Your plant is reacting to the repotting that you did that was not necessary. The fungus gnats were introduced with the soil that you used. Sand on the surface is not an effective treatment as it keeps the soil below from drying out properly.

Remove the sand and any soil you added to the top of the original rootball when you repotted as that soil prevents oxygen from penetrating the root zone readily and makes it harder to determine when to water. Then, allow the top inch of the remaining soil to get dry before watering thoroughly.

The outside sun is very intense so make sure your plant is positioned so that the sun never falls directly on the leaves at any time during the day.

I thought about that possibility, but the soil that I used was just bought. I repoted it because the wood pole that was in it was rotting, ND the top of the soil that it came in was strange, maybe with over salt. At this point some of the leaves were already showing these signs, they didn't appeared after the repotting, they were already there. So I changed the pole and also the substrate carefully to not to damage any root.

About the sand, I use it on all of my plants and it was the most effective way to control fungus gnats here. I tried everything. Traps, hydrogen peroxide, organic control, using sphagnum to cover the top layer but still the fungus gnats found a way to enter the soil. I always wait until the first inch of the soil to dry, always. When the toothpick comes out dry i know it's time to water. That's why I thought that it was fungus!

I suspect that you have been inadvertently overwatering all along. Best to let the soil dry deeper into the pot. Letting the upper portion of the soil get as dry as possible is the best treatment for gnat larvae and will probably be a beneficial for the plant, as well.