You may have already known, but certainly after attending the last two Mulch 101 sessions, you understand that using mulch on your plantings is beneficial. Organic mulches in particular add organic matter to the soil while they conserve water, moderate soil temperature, and suppress weeds. Many beneficial fungi and bacteria help decay the mulch to release nutrients that help plants grow.
Wood and bark mulches are particularly popular and even come in designer colors. Wood and bark mulches unify the planting bed or border and make it more visually appealing. Don’t be surprised, however, when admiring your mulch after a period of wet weather you see something that looks like a monster’s fingers writhing out of the ground! Don’t panic and expect the worst – like a dead body buried underneath – since the fingers are often accompanied by a foul smell. In fact, don’t worry at all. You have just come across a fungus growing on your mulch that is a member of the group known as the “stinkhorns”. These stinky and startling creatures are nothing to fear.
You might also come across an equally gross looking slime mold – a fungi known commonly as dog vomit. It grows over the top of the mulch and can grow up to three feet in diameter. It may be yellow or orange but turning brown later on. Slime molds are also harmless, but are actually able to move very slowly over the top of the mulch – reminiscent of the classic sci-fi monster – “The Blob.”
Most of the mushrooms and molds commonly found in mulch are harmless. The bird’s nest fungus, a common fungus that is prolific on hardwood mulch in fall and winter, looks just like a miniature nest protecting small eggs. This fungus is brown or grey in color and only 1/4” across. If nuisance fungi are causing a problem in your landscape, switching from hardwood mulch to pine bark mulch or pine straw may reduce the problem. Watering hardwood mulch well when it is first applied can discourage the growth of nuisance fungi by encouraging beneficial bacteria.
Generally, it is best to be patient and let the monsters die out on their own – just like in War of the Worlds. If you see one of these monsters, the thought of eating them will not cross your mind. Just remember NEVER eat a fungi or mushroom that you do not positively identify as safe to eat, no matter what it looks like.
Direct comments or questions concerning this column to Marilyn Odneal via email at MarilynOdneal@missouristate.edu.
