A Gardeners Forum Forums Gardening Reference Gardening in 2006 Is it ok to change my rubber plant's soil?

Recently my niece gave a rubber plant she didn't want. It came from a large discount chain that I particularly hate getting plants from. Every time I've gotten plants from one of these stores I've had a problem. Most of the time it's been fungus gnats. One time mealy bugs.

Anyway, the medium they use also stays wet waaaaaay too long. Then that icky white stuff starts growing on the top of the soil (fungus? mold?)

Anyway, I would like to change the soil, but keep the plant in the same pot. The plant seems to have already adjusted pretty well to it's new environment and has already grown new leaves. Can someone give me pointers on how to do this as safely as possible?

Hi Amany,

Total soil replacement is like getting a heart and lung transplant. It shouldn't be done except when there is no simpler alternative. Evidently, your plant is healthy and doing well. Don't let previous bad experiences determine what you do in this instance.

Does this plant have mold growing on the soil? Are there crawling insects in the soil? How long does it take this plant to dry out in between waterings? Does this plant have mealy bugs?

It is always preferable to deal with a specific problem rather than trying to fix multiple problems that might occur in the future.

Will Creed
Interior landscaper

There is mold growing in the soil. Gnats arrived soon after I got it. I have not seen any other pests.

It's in a 3.5 - 4" pot. When I water it, the soil stays moist for about 7 days. It feels almost as wet as it did the day I watered it. I have it about 8 inches away from an east window and it doesn't sit in water. I do have a pebble tray underneath, but the bottom of the pot doesn't touch the water at all. Shouldn't the soil be drying out sooner?

Oh, and there are plenty of drainage holes.

I suspect that it was not well-cared for at the chain store - probably over watered and exposed to other plants with fungus gnats.

A week between watering is about right, even for a small plant. As long as you allow the top inch or so to dry out between waterings, it should be OK. In fact, allowing the soil to become dry will help deter both the gnats and the mold.

Scrape off all the loose soil and mold from the surface. More mold may come back, but just keep scraping it out and it should gradually diminish. A thin layer of builders or river sand sprinkled on the surface of the soil will carve up the fungus gnat larvae when they try to emerge from the soil. That, in combination with keeping the top inch of soil dry, should lead to a gradual decline in the gnat population.

Alternatively, you can put half-inch slices of raw potato on the soil surface. This will attract the larvae. Replace the slices every day or two until you no longer see the larvae on the slices.

These solutions will not stress out your plant and are usually effective.

Let me know if this is unclear.

Will, I love it when you show up!
Thank you very much.