[Robert A Cook PE]

Do pine trees need dirt to grow?

(All we've got here is a 6" deep layer of slimy, greasy, slippery densely packed red clay....)

(However, I'm pretty sure a moderate acidic soil helps both cedar and pine - and you've got the limestone rock in the aquifer down below... could be pretty basic up top as well. Which might be why cedars don't get too tall in the Hill Country.)

Virginia put this out:

http://www.ext.vt.edu/pubs/trees/430-027/430-027.html

'Course, no soil, rocks, and low rainfall don't matter, do they?

[Robert A Cook PE]

This one sounds like a nice tree for the Edwards: but it seems to be a slow grower though... Bummer: 8<(

http://www.fs.fed.us/database/feis/plants/tree/arbtex/botanical_and_ecological_characteristics.html