Tuesday, June 26, 2012


Wainaku Grass deep beneath Garden Bed

  I just spent four hours double digging a garden bed that had become overtaken by Wainaku Grass.  It is also known as "Torpedo Grass" as it sends out roots very deep.  It must like anerobic conditions as it most often travels along the clay just below the prepared garden.  This makes it very difficult to combat.  You just can't weed the surface.  One must turn the entire garden bed, one shovel full at a time, throwing the dirt in such a manner as to expose any roots that may be in that shovel full of dirt.  So each shovel of dirt must be sifted through to pick out the roots.  Even the smallest root left in the garden bed will grow and be the nexus for the invasion.

Garden Bed after de-Wainaku process

Master Cho suggests no till.  However, Wainaku is so aggressive, I'm not sure desired plants could compete.  I won't till this bed again.  I'll let the insects dig their air holes in the soil, the microbes establish their environment, and I won't disturb it.

Wainaku Roots

During this process I did notice that the soil just under the weeds was very healthy.  It was darker in color, and in granules.  It also had lots of worms.  This must mean that the weeds are adding fertility to the soil.  I used all the weeds and roots removed from the garden bed to mulch a near by avocado tree.  Thinking that these have lots of good nutrients.

1 comment:

  1. Won't using the roots for mulch just spread the grass? It sounds a lot like the quackgrass we used to battle in Idaho. The only way to be sure each root segment died was to let it dry out on the fence for the summer... or so said the old-timers. Seemed true enough. I wonder if pigs could eat them?