Thanks. I am going to put it on concrete instead of lawn / soil, then
and then maybe use bricks to shim it up to minimize ground contact.

Can you recommend any product that is preferably clear but will seal
the wood against termites and dry rot? Something like a laquer,
polyurethane, stain so I could think about it some more. I do not
wish to attract termintes near my home, do the sealers help protect
against insects?

I might just use a plastic pot as a liner and modify the bottom
material of the planter, so the wood does not need to be wet during
watering.

I know fir it is not the choice of the wood for outside, rot resistance
wood for the same item would cost 3 times at much I would think. I
don't expect this to last forever.. just a way to prolong it's life no
matter what it is made of, which is why I'm asking the question here.

Thanks