In my 9/21 post I described various tactics I am using to eradicate Bermuda grass organically and how I covered an area with 6mm thick commercial grade black plastic. Bermuda grass likes heat and rather than try solarize it with clear plastic (and this would only have possibly worked if I had tried this before the onset of summer), I thought completely depriving it of light might be more effective.
Today, some 3 months later, I decided I needed some of the covered area to plant out my remaining garlic cloves. Also I was curious to see what effect the exclusion of light had on the bermuda grass.
I lifted some of the black plastic covering, forked up a chunk of soil and pulled on the Bermuda shoots. To my surprise they slipped easily out of the soil, much more easily that an adjacent area which I had just finished clearing. So I decided to look more closely and noticed that the fungi strands on the ground, which I associated with the wood chips I had dumped the previous year, were actually decomposing the roots on the Bermuda grass shoots. Without their roots, the Bermuda grass shoots slid easily out of the moist soil.
So the fungi attacked the roots. I am assuming this is decomposing (saprophytic) fungi (rather than parasitic) and they migrated from working on the wood chips.
This could mean that either the Bermuda grass had died or had gone into a very deep withdrawal. Bermuda grass hibernates every winter – it turns white and to northern visitors looks as if it is dead. But in the spring the green shoots appear and, as the weather heats up, it comes vibrantly to life. But I have not seen fungus attack overwintering Bermuda, so it seems likely that the black plastic covering had a significant effect.
I shall leave some of the covering in place through spring and then see if the grass can rejuvenate itself, and if it doesn’t then this will be a viable non manual yet organic way to combat Bermuda grass – establish fungi, seclude the grass from light and let the fungi do their work.
In the meantime I shall continue clearing the now vulnerable Bermuda grass from more of the area so I can install garlic and several varieties of kale which should do well in the winter in this very sun exposed site.