Fairy Ring Type of Mushrooms
Brian Jervis: Ask A
Master Gardener
Tuesday, August 19,
2017
Q: There are mushrooms
all over my yard and that of my neighbor’s. Are they harmful? What should I do
about them? Tom B., Jenks
A: The summer of 2017 has
been a bit abnormal. We have had few century-degree days and much more rain
than usual. While the rain is truly beneficial to our flower beds, gardens and
lawns, it can cause other undesirable issues, such as mushrooms and fairy
rings.
Mushrooms are actually
part of a fungus that grows underground, well hidden from sight. Your yard is
naturally full of fungi (plural for fungus) and spores, some harmless
and some problematic. Fungi are interesting as they are one of the few things
in our yard that do not get their nutrients from photosynthesis. Fungi receive
nutrients by either decomposing or consuming organic matter.
Another phenomenon of
mushrooms is commonly known as a fairy ring. These rings are also known as
fairy circle, elf circle, elf ring or pixie ring and are produced by many
varieties of underground fungi. Fairy rings are simply an organized pattern of
fungi, typically circular in nature. They typically expand from a central point
into an arc or circle and are particularly noticeable when they grow in our
lawns.
The ring’s appearance
is variable and may occur in all types of turf grass. They may appear as green
rings, brown rings or simply a ring of mushrooms. The rings range from a few
inches to many feet across and may persist for years.
The fungus that causes
these rings feeds on organic matter in the soil. As it feeds, it frees up the
nutrient nitrogen in the organics, accounting for the dark green rings.
Typically, most lawn fungi and their mushrooms don’t actually harm the health
of a lawn. However, in some cases, the older fungal mass may be dense enough to
prevent water penetration and actually starve the grass from nutrients, thus
producing a ring of dehydrated dead grass.
Mushrooms, toadstools
or puffballs may appear overnight, especially after a rain. They are the
fleshly, spore-bearing fruiting bodies of the underground fungi. To be on the
safe side, all of these mushrooms and puffballs should be considered poisonous
and should be removed as soon as possible.
Management is not
easy. Once the disease appears, it is difficult to eliminate. There is no
natural control. Most people opt for greening the lawn with recommended amounts
of nitrogen fertilizer, which effectively masks/hides the ring but does not
eliminate it. Other measures you can take: remove mushrooms by regular mowing
or raking; water deeply to minimize the loss of grass due to the fungal
dehydration; remove excess thatch and aerate compacted soils; encourage beneficial
soil microbes by top dressing with a humus builder, such as well-aged manure or
finished compost. However, if grass is lost, reseeding or re-sodding may be
needed.
There are fungicides
labeled for fairy ring control, but most are not effective and usually require
a certified professional for application. Your mantra should be to fertilize,
water, aerate and mow. Unfortunately, the only option for complete elimination
of the fungus is to remove and replace the soil and grass.
Garden tips
·
Always
follow directions on the labels of synthetic and natural pesticide
products. Labels will always list where the product may be used and which pest
it is certified to cover. If you spray pesticides, do it early in the morning
or late in the evening after bees have returned to their colony.
·
If
your tomatoes are too tall and gangly, now is a good time to prune the top of
the plants by as much as ⅓ to ½, depending on the plant. This will
stimulate new limb growth and new fruit production after it cools.
·
Reseeding
fescue is best done from mid-September through mid-October. If you plan on
reseeding, begin scouting for good seed, there is no “best” variety. Purchase a
fescue blend of three or more varieties, with or without Kentucky bluegrass.
Read the label on the seed bag. A good blend will have 0.01 percent or less of
undesirable “other crop” seeds.