Mushrooms in the Garden Beds

You may have seen some mushrooms popping up in your garden beds. Usually, you see them most in beds that are mulched with bark or shredded wood; essentially a recycled wood product. The Texas Plant Disease Diagnostic Lab gets a lot of questions with regards to these sightings, everything from “Is it dangerous?”, “ Is it poisonous?”, “Will it kill my plants?”, to “How do I get rid of it?” Let’s break it down.

It is dangerous? The short answer is PROBABLY NOT. Many times, the mushrooms you see are fruiting bodies of fungi that are present in the soil or on the wood. The role of these fungi is to help breakdown the wood material. They are an integral part of the ecosystem cycle.

Is it poisonous? This is a tougher question, because it depends on the fungus. A good field identification guide will help with figuring out what the fungus is. The usual practice is to NOT eat a wild fungus unless you are 100% sure of its identity. The spores produced by these mushroom can be an allergen to a small percentage of folks. What about pets? Please consult a veterinarian if the situation occurs: if possible, take a photo of the mushroom. A physical sample is helpful but remember that the mushroom may breakdown rapidly.

Will it kill my plants? Unlikely! In some cases, these mushroom may be beneficial to the plants. By breaking down the woody “waste” material, they are returning nutrients to the soil which then can be used by plants. Then again, something like SLIME MOLD can smother and overwhelm small plants.

Slime mold on a rose plant

How do I get rid of it? Most mushrooms are delicate and will break down relatively quickly. Many mushrooms associated with the mulch may be present only a few days. The breakdown can be hastened with disturbance (ie. chopped up, broken, crushed). You can use a jet of water to break up the mushroom (works well on delicate mushrooms and slime molds) or use an instrument such as a rake to break it up. But for these types of mushrooms, there are no approved fungicides.

Why are these mushroom popping up when we are so dry? While general conditions may be dry, landscape beds are usually irrigated. When conditions are right – where water is available to the fungi and environment is at the right humidity and temperature, mushroom will make itself known. The key is availability of water to the fungus. In a garden bed, irrigation to ensure that plants are watered also provide water to the fungus.