rhubarb seeds

The quickest way to propagate rhubarb is to divide a plant. Any chunk that has a stalk or two and some roots will probably grow. Seeds will work if they are viable but it will take longer. AFAIK rhubarb is true breeding so the seeds should give a plant much like the parent.

Sure, depending on your definition of 'very large'. Fill the pot with fairly rich mix that includes some manure or compost, rhubarb is a moderately heavy feeder. It will only do well for a year or two after that divide it and plant it out or replace the soil. Place the pot in full sun and remember to water it regularly particularly when it is hot and dry.

David

Same here 100 miles west of Montreal. Local plants are hardy i.e. survive winters as cold as -30, appear dead in April and produce edible rhubarb in June.