most durable planters
looking for the most durable planter material to be used all summer for plantings and to be kept out in winter,possibly with small tree.
need advice which is the most durable material..which will not crack or easily break or be destroyed by very cold temps (minus 20 C )..even with small tree inside (calculating for possible expansion)
would polyethlyne, or resin or fiberglass or other be best for our growing
need people with experience to respond, if possible.