I had these really strange looking – and bad smelling - growths in a
couple of my landscape beds last September.
Can you tell me what they are and if they are harmful to people or
Can I spray something to get rid of them?
A. The writer included
some photos that showed stinkhorns growing in her landscape beds.
They looked most like dog stinkhorns (Mutinus caninus).
are relatively common in mulched areas and even lawns when
environmental conditions favor their development. Warm, humid
weather, frequent rain and moist soil favor the growth of many fungi
common in areas rich in organic matter.
Life Cycle of Stinkhorns
Stinkhorns typically appear from late summer into the fall,
appearing as yellow-orange to bright orange, finger-like stalks that
grow from egg-like structures half buried in the soil or mulch. The
stalks are topped with caps of brownish-green slime that contain
spores. The cap develops a putrid smell in order to attract flies to
land and carry spores off to germinate elsewhere.
listed them as inedible, but none listed them as toxic. The smell
alone should discourage sampling, but you can dig them out and
compost them or send them out with the trash if you are concerned
about children eating them.
Photo: Sandy Feather
saprophytes, a large group of fungi that break down organic matter
in order to absorb nutrients from it. They do not cause disease in
live plants, so your landscape plants are in no danger from them.
Other familiar saprophytes are bird’s nest fungi and slime molds
(often called dog vomit fungus), commonly found in landscape beds
mulched with shredded wood or wood chips.
There is nothing homeowners can apply to stop stinkhorns – or these
other saprophytes - from growing. I noticed some websites
recommended spraying fungicides, but there is no research-based
information to support doing so. The best recommendation is to
ignore them. They shrivel up and disappear almost as suddenly as
they appear. If they are too numerous or otherwise disturbing, you
can physically remove and dispose of them.
Where do Stinkhorns come from?
These fungi are
part of the natural decomposition process that includes the activity
of fungi, bacteria, insects and other arthropods, birds and mammals.
Stinkhorns grow in wild areas as well as more urban places – all
they need are the right weather conditions and a substrate of
organic matter. Of course, the transformation of organic matter into
humus that in turn improves soil structure and enhances growing
conditions for all plants is one of the reasons we use organic
mulches in the first place. Few people even notice the activity of
these fungi in natural areas where they turn fallen trees into nurse
logs that nurture germinating wildflower seeds and young saplings.
They are just doing their job.