White Web-Like Fungus in Mulch: Harmful to Plants?

Question: After using cedar mulch, I notice clumping, a white thread-like web, powdery texture, and a distinctive smell in spots where plants died. Is this a fungus? What should I do?

Diagnosis

It's a fungus growing in decomposing mulch, but it's not harming your plants. Something else is causing the die-off. If only roses are affected, suspect leaf diseases and insects. If everything is affected, check drainage, root rot (a different fungus), or vole damage.

Recommendations

Avoid over-improving soil, which can hold moisture too long. Plant high for good drainage.