Question
Can I plant a Niagara Grape Vine in a pressure-treated wood box container on a deck to grow up over a pergola?  I live in central Ontario and the vine will be in full sun.  I really want the "pressure-treated wood" part of the question answered.  I don't think I'll have a problem growing the vine, I just don't want the treatment to hinder it's progress.

Answer
To be on the safe side, I would coat the lumber to seal it.
When you have finished the box, go to the auto parts department and ask for a sealer for the underside of the car. It is to protect the car from corrosion. Drill the drain holes in the bottom of the box. Paint the entire inside of the box with the sealer, including the drain holes. Let it dry for a few days before you plant.
Give the vine good soil, plenty of water and sun. It will be beautiful on your pergola.

bakerplanter