What is this white stuff and how do I prevent it? - Ask Extension
Hello! We put mulch down this spring after clearing out our back and planting some viburnum, sweet pepper bushes, and mini dogwood shrubs. The last we...
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What is this white stuff and how do I prevent it? #874147
Asked June 22, 2024, 6:22 AM EDT
Hello! We put mulch down this spring after clearing out our back and planting some viburnum, sweet pepper bushes, and mini dogwood shrubs. The last week I’ve noticed this white stuff appearing quickly in two different spots. Do you know what it is and how I can effectively remove it and prevent it? Thanks!
Howard County Maryland
Expert Response
Fortunately, the residue pictured on the mulch is harmless, and it will go away on its own. It's a slime mold, which are colonial microbes that consume other microbes (they don't infect plants), and they often disappear almost as quickly as they appeared. You can learn more about them (plus other harmless fungi that appear on mulch or garden beds) in these links:
If too bothersome, you can scape up the clumps and toss them into another part of the yard, though conditions with frequent wetness (like sites near a leaky faucet, a dripping gutter overhang, or areas that might be irrigated too often) might encourage their return in the future. There is no way to prevent slime mold "outbreaks," but moisture management by avoiding over-watering (if applicable) can help if it's appearing often.
Miri
If too bothersome, you can scape up the clumps and toss them into another part of the yard, though conditions with frequent wetness (like sites near a leaky faucet, a dripping gutter overhang, or areas that might be irrigated too often) might encourage their return in the future. There is no way to prevent slime mold "outbreaks," but moisture management by avoiding over-watering (if applicable) can help if it's appearing often.
Miri
