Farmall Cub

Organically speaking would you line the inside of a raised bed frame?

First off, I have never planted in a raised bed so I am not sure I should be responding. But, by lining the frame with plastic, etc., I would think that the rain water would not be able to drain out, leaving the bed soggy. Might not be good for the plants. If you were to use the fabric type liner, it would let the water out. But if you are having a drought like we are having here, the rain water would not be a problem.

I think the question concerns lining the frame's interior walls, not the bottom.

I have used raised beds in the past. Never lined the interior walls. Used only untreated 2 by lumber. Lag bolted. Only problem, if it's a problem, is that the frame will rot out after a number of years.

My daughter uses large tractor tires as raised beds. Cuts off one side wall. Works quite will. Guessing they are around 20 years old and still in good condition.

As Eugene said, don't use treated lumber, but no need otherwise to coat the interior of a raised bed.