Growing Concerns 580: Mushrooms in lawn, something stripping bark

Late Summer!

Time and tolerance are the best answers when mushrooms mar the lawn


Dear Janet,

In the past two years, I have had toadstools popping up all over my yard. I have called landscapers, gardeners and nursery personnel to see what I could do about this problem. I have my lawn sprayed for weeds, bugs, fertilizer, etc. The answers I have received go from 'do nothing' to 'redo your lawn after digging everything up.' I am in a quandary as to what I can do as I have a beautiful lawn except for those darned toadstools.


Dear B.G.,

Toadstools are types of mushrooms, and wet years like this one are banner years for mushrooms. That's because wet years are good for fungus growth, and mushrooms are the reproductive bodies that fungi produce when they have energy to spare.

The fungus that's interrupting your greenery is probably one that decomposes wood. It may be growing on dead and injured tree roots. Such fungi are always present in the soil but multiply when they have more fuel and moisture. That's why we see mushrooms after we cut down a tree.

There isn't any practical answer. For instance, digging to remove all woody roots from an area can work but it means excavating a huge area a couple of feet deep. In addition, such digging would destroy live roots, too, killing or injuring any trees in the vicinity.

I guess you figure there must be an easier way, perhaps a chemical solution. Forget it. Even if you could sterilize the soil to kill all the fungus in it, you shouldn't want to. Fungal threads are one of the primary binders of soil particles. They create that crumbly soil where air and water flow freely and roots thrive. Fungi are also critical to decomposition. Without them, dead plant and animal matter would remain intact, and accumulate -- think of the clean up work we'd have to do. Even more important, think of all the nutrients tied up in dead organic matter that would never be returned to living plants.

Mushrooms don't harm a lawn, only our sensibilities. Mow them when they appear. When the wood that's fueling their production is gone, the toadstool show will slow and then end.


Dear Janet,

In this past week, something has been stripping the bark off my maple and beech trees. These are small to medium trees, eight to ten inches in diameter. We noticed the piles of bark strips, about an inch wide and three or four inches long, beneath the trees. Several areas have been stripped bare, even girdling some areas.

We have a small area of natural woods along our back yard and have already lost ten trees, and now these. Are squirrels doing this? Can we save these trees? How can we prevent this from happening? We have been here for seven years and have never seen this stripping before.


Dear C.W.,

No one knows why, we just know squirrels do tear bark from trees. The squirrels may lick the wood they bare, as if they are thirsty or enjoy the taste of sap. But many reliable witnesses have documented long bouts of stripping without any feeding activity. My own opinion is that squirrels just have it too easy. Bored and lacking anything better to do, they peel bark. Perhaps if there were fewer bird feeders so squirrels had to work for a living, we'd see less of this.

It's nearly impossible to keep a squirrel out of a tree, or to protect the trunk and branches of those they do climb. Which is why, when squirrels in botanical gardens and arboreta start stripping bark, they are trapped, relocated or executed.

Short report

Time to clean up summering-out houseplants

You have asked if soap spray is good to use on houseplants before bringing them in from their vacation on the porch, whether it will knock off mites and insects.

It's good to clean your plants regularly, indoors or out. It removes dust so leaves work more efficiently and mites find it less hospitable, it knocks off insects and eggs, and it makes the plant look great. However, a one-time cleaning makes little difference in the long haul, whether it's February and you're cleaning a housebound hoya or late September and you're hosing off a bay tree before it comes in for the winter.

I don't do special pest control on my plants when I bring them indoors. They are in peak condition from fresh air and good light, able to produce their own insecticides and miticides. I just hose them off and bring them in.

For plants with problems, indoors or out, I add a presoak to bath day. I move the plant out of the direct light, cover the soil in its pot with plastic wrap, then spray with a Murphy's Oil Soap solution -- two tablespoons in a half gallon of water. I coat both sides of every leaf and double spray the tight places where leaves join stems. After the plant sits for fifteen minutes, I hose it off with a strong stream of water.


Green thumbs up

to the spicy scent of summersweet (Clethra alnifolia), the shrub that brightens shady areas in early August and loves rainy years.


Green thumbs down

to blaming anyone or anything for the mildew that ruined your cosmos or phlox. It's been rainy. Mildew happens. Get over it.


 Originally published 8/21/04