What is that smell?
If you are talking about a terrible odor in your yard, it could be the scent of stinkhorn fungi.
Late winter into early spring in Central Florida is the time during which stinkhorn fungi make an appearance.
The weird fungal growths are not harmful.
In fact, they are quite beneficial organisms that decompose dead plants and animals — recycling those nutrients back into the environment.
While related to mushrooms, such as puffballs and earthstars, stinkhorn fungi are very unusual in appearance, often keeping their identity a mystery to those finding them simply because they don’t really look like anything else you might have seen.
You may not even see them in the environment due to their odd appearance, but you’ll certainly smell them.
Stinkhorn fungi are aptly named due to the putrid aroma that emanates 20 feet or more away from the actual fungus.
Stinkhorn fungi are very commonly found growing in landscaping mulch and compost, which they are slowly decomposing and using as a food source.
These fungi prefer the cooler months and usually emerge from below ground following a rain event.
Most of the stinkhorn’s body is underground and a white, egg-like protrusion is the first indication that one is emerging. The rest of the stinkhorn’s body will emerge over a few days.
Depending on the species, they might look round; be an upright, tubular protrusion; or even have a lattice-like network of filaments. The color ranges from yellow to orange, and maybe even red.
Stinkhorn fungi gradually decompose over a four-day to five-day period as they complete their life cycle.
Early in their development, the fungi will emit a foul odor that can persist for days. Some say the odor smells like rotting flesh, while others might say it smells like rotting eggs.
Recently, a homeowner called the Pasco Extension Office concerned about the smell of methane emanating from the yard. Upon further investigation, it was determined the cause of the smell was a stinkhorn fungus.
While we won’t appreciate the rotting smell associated with these fungi, it is essential to their survival and spread to new areas. The smell attracts ants, flies and other insects that will carry the spores (microscopic seed-like structures) to new locations with more food sources.
Luckily, stinkhorn fungi are harmless to landscape plants, trees, shrubs and so on.
Stinkhorn fungi, as well as other decomposers, help to break down tiny pieces of organic matter helping to build a healthier soil profile, which then can support plants much more effectively. This benefit is really important considering Central Florida soils are very poor with little to no organic matter and low water-holding capacity.
Since stinkhorn fungi are beneficial, and not harmful, there’s no need to try to control them.
If you notice stinkhorns in one place, it’s possible you’ll continue to see them in the same area for several seasons. If they are troublesome due to the smell, simply place a plastic bag over the egg-like protrusion as soon as you notice them, collect the fungus, tie up the bag and throw it away.
Allowing them to mature will increase the chance that they will spread, as will running over them with a mower.
Looks — and smells — can be deceiving in the landscape.
Do some research on land-grant university websites, or better yet, call your local Extension Office to get help identifying unusual things in your landscape. You just might discover that they are more helpful than you could ever imagine.
Dr. Whitney C. Elmore is the UF/IFAS Pasco County extension director and an urban horticulture agent III.
Published March 03, 2021