Soil staying damp for too long can cause fungus to grow on the surface.The fungus itself won't hurt the plant, but constant damp soil can. The soil could even be heavy and/or maybe not draining as well.
If you want to get rid of the white fungus, just scoop out the entire top couple of inches or so of soil trying to get all the spores and replace with new dry soil.

Billy Rae

Oh, hi Billy Rae, posted while I was in the middle of writing my post. Not to be argumentative, but I have never had success with replacing soil. Has soil replacement worked for you in the past?

Larry

Hi Larry!

I can honestly say that scraping the top part of the soil out has worked for me. I think the the trick is to get ALL of the spores out and of course, not over-watering, or having poor drainage/big pot, that kind of stuff...
This was something that happened a few times when I first started collecting houseplants many moons ago. At the time I didn't even know what that nasty white fluff was or where it came from. I'd scrape it out with a big spoon down a couple inches to near the top of the root-ball.

I have heard of using Tinactin on fungus soil and have heard good things about it!
With better understanding on my part of a plants basic care, a fungus problem is a thing of the past.

There can sometimes be more than one way to go about eliminating a plants problem and so I'm sure using Tinactin is just another successful way to go about it.

Billy Rae

Hello there.

I am a palm in my house that I bought a few weeks ago. I used Fafard all purpose soil. When I bought it, it was really wet.

My palm's soil surface has some white fungus growing on it. I have no idea what else to do to get arid of it. I tried to scrap of some of the soil and replace it, but it came back.

Here is a link that might be useful: {{gwi:103766}}

We have some of this white wispy-type of fungus on a few outdoor plants in buckets. My son mixed hydrogen peroxide (household type) one part to two parts water and sprayed it on the surface a couple of times. The fungus has disappeared. Thought this might be helpful.

And, P.S. We have had a ton of rain and lots of humidity for quite a while. I am sure that adds to the problem.

The fungus is harmless. It is just evidence of decomposing organic matter in the soil, which is often stimulated by heat and moisture. Or a potting mix that contains more moisture retentive OM than is ideal :-)

It won't hurt the plant and attempting various methods of removal could prove far more damaging. It's a pretty cyclical situation and will disappear in time. I'd just leave it alone.

The peroxide works for me all the time. Once mold or fungus is in the soil, short of removing all the dirt, cleaning the pot in a bleach solution and disinfecting the roots of the plant with peroxide, it never goes away. As soon as the damp conditions return the problem just starts all over. The spores have to be killed. I have seen mold and fungus destroy the plants at the root and stem level. Peroxide is the best option.

Let's be clear here......mold or fungi growing on potting soil is NOT harmful to plants. It is a perfectly natural process that is reflecting the decomposition of the organic matter in the potting soil. Not all fungi are harmful - most are just natural decomposers and are essential elements of successful gardening. Decomposing fungal organisms - like what you may find growing on potting soil - do not infect plants so there is no need to remove.

If the fungi/mold concerns you or you dislike the appearance, try addressing the causes rather than the symptoms. And the causes are a less-than-ideal potting medium with inadequate drainage and porosity and improper watering practices. The soil is simply staying too wet and warm, encouraging the visible growth of the fungal organisms. And it is not the mold or fungi "destroying the plants at the root and stem level" - it is the conditions that allow them to proliferate: poorly draining, excessively moisture retentive potting soil and too frequent watering. Peroxide is NOT the best option - a better potting medium is.

FWIW, I grow extensively in containers, both indoor and outdoor plants. But I use a very high quality, fast draining durable potting mix (like Al's 5-1-1 or gritty mix) and I have NEVER had mold or fungal growth appear on the soil.

What Pam said immediately above ..........

Al

Let's be clear here...If you've never had problems with mold because your soil is so perfect and your water and watering techniques so good, how do you know whether or not fungus causes damage? It DOES. I have dealt with it in humid climates for over 50 years in plant keeping. While some fungi are harmless there are some that cause softening of the bark at the soil level exposing the xylem and stunting the growth of the plant. I have plants that needed re-potting due to poor soil but fungus reappeared with proper watering techniques. Problems stopped after applying fungicide even with same soil and watering techniques. Whenever I have this problem I have used fungicide I get from an herbalist who sells the stuff to me at a very reasonable price. The formula is proprietary. It is sprayed on once a day and works within a couple of weeks. She did tell me that it has H2O2 in it. Mold smells bad and some of us are allergic to it...so it's not a good thing and ask any allergist if it's harmful. It can a cause violent reactions in a significant portion of the population. You don't want it in your potted plants.