Mycorrhizae, Moss, and Baby Tears

What if Darwin’s “survival of the fittest” theory was wrong?  What if it turns out that “survival of the most cooperative” explains why some species are more successful than others?
Research conducted in a forest of Douglas fir and birch trees demonstrated the cooperative relationship not only between fungi and trees, but between trees of different species as well.  Fungi known as mycorrhizae are considered to be appendages of forest tree roots since they absorb water and minerals that are directly channeled to the roots.  These fungal appendages, in turn, are fed carbohydrate from roots which allows them to grow and expand their absorptive capacity for the trees’ benefit.
Mycorrhizae also form an interconnected network, a single, multi-tentacled organism serving as water and mineral conduits to the roots of many trees growing together.  It was found that birch trees transfer carbohydrate through mycorrhizae to adjacent Douglas fir trees that are under stress.  It is hypothesized that mycorrhizae may form a sort of biological Internet that connects each forest tree to every other, to the benefit of them all.
I started to think about fungi, especially their underground presence, upon receiving the following email several weeks ago:
“I noticed this crusty, gunky white stuff growing around the base of a shrub.   I thought it was caused by too much water, so I removed it and turned the sprinkler head around so that the base of the shrub would not get wet.   But the white stuff came back within a week.  What do you think it is, and should I just try to remove it again, or is there a product I can use?”
— Janice Biermann, Santa Monica

fungus that disappeared following application of solution of 1 tablespoon of vinegar in 1 gallon of water

I sent Biermann a list of homemade remedies for combating fungi.  She tried an apple cider vinegar treatment, where you mix one tablespoon of vinegar in a gallon of water and spray, and the “white stuff,” a fungus, disappeared.  This same formula is also recommended, incidentally, for control of black spot on roses.

The fact that Biermann’s initial removal of the fungus did not prevent it from coming back again illustrates the staying power of fungi.  The fungus you see on the soil surface is only half of the story.  The visible mycelium or body of fungal strands extends into the soil as well.  Even removal or digging up the fungus, without some sort of systemic treatment, will not eliminate it since even tiny pieces of fungal strands can quickly regrow into a fresh white mass.
Fungus is not the only undesirable visitor to a shady garden plot as an additional email from Biermann revealed:  “Because of all the rain we’ve been getting, there is quite a lot of moss growing in my flower beds.  I am trying to scrape it off, but wonder if you have any tips?”
Popular treatments for moss build-up include application of iron rich fertilizer such as iron or ferrous sulfate, spraying a dish soap solution (2 parts dish soap in a gallon of water), and, once the moss is gone, covering the bare spots with a rough mulch such as wood chips.  There is also a natural product called Mossbuster that you might want to try and that may be ordered through

baby tears (Soleirolia soleirolii)

Once the moss is vanquished, you might also consider planting something that will spread to cover the gaps. Although it has gone out of style in recent years, baby tears (Soleirolia soleirolii) is a wonderful ground cover for the shade.  I know, it can be invasive, but it is so shallow rooted that there is never a problem plucking it out to keep it from growing into other plants.

Tip of the Week:  If you want to harvest herbs but do not have a garden, you can do so by positioning them, in containers, on a sunny window sill.  Spearmint and peppermint are the most rapid growers and can make do with less sun than most herbs.  Lemongrass is also recommended but will need full sun.  Mint cuttings and lemongrass stalks are easily rooted in water.  With mint, detach three inch terminal pieces and, in the case of lemongrass, entire stalks may be used, whether store bought or procured from a friend or neighbor.  Place mint cuttings and lemongrass stalks in one to two inches of water, change the water daily, and you should begin to see roots within two weeks.  At this point, you can transplant your herbs into containers filled with your favorite potting soil.  Basil shoots, taken from store bought clumps, can also be propagated in this manner although you will have to wait a little longer to see roots.

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