styrofoam, heavy pots, water column, etc.
Fri, 11 Feb 2005 10:22:50 PST
Hi Gang,

I have used styrofoam slabs in the past with good effect to:
1.  make the pot lighter,
2.  work with deep growing roots, and 
3.  cool the soil.

I used styrofoam logs about 1 or 2 inches on a side and about 12-18 inches 
long.  I set them vertically in the pot and filled in between them with regular 
soil mix.  The vertical arrangement allowed a deep root run, but the styrofoam 
helped make the large pot noticeably lighter.  

The best part was that by strategically placing the styrofoam I could limit 
some soil heating, not a lot but enough that I could measure a few degrees 
difference (compared to non-styrofoam--containing pots).  The soil in the back 
side of the pot (away from the sun) did benefit--I presume it was just simple 
insulation effect due to styrofoam.  

Perhaps there is no difference for plants if I should use styrofoam peanuts, 
or styrofoam logs, in terms of possible toxic effects.  But, for sure, the 
logs did not seem to provide much in the way of air exchange as I hope to obtain 
with the peanuts.  I'm hoping for great things from the 
peanuts-as-soil-amendment experiment.  But, like so many things in gardening, what we hope for and 
what we get are often different entities.  

As I think about the styrofoam logs I suppose any cooling benefit would not 
be felt if I had better shade for my pots, or in areas without hot, hot summer 
sun.  So much about soils, especially potting soils, seems to be climate or 
season specific.  


Conroe Joe

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