These Shrubtubs Square CorTen and Tree Tubs are normally made of 4mm - 0.15” thick CorTen steel. They contain a volume of substrate up to a maximum of 5m³ - 177 cu ft. and are suitable for shrubs, multi-stemmed trees. Bigger city trees depend on this substrate volume. The Treetec® Bottom Up nursing system is optional. The CorTen tub is well detailed, functional and deliverable with a special double powdercoating. The Shrubtubs are easily relocated and have anchoring for the root ball. The single-walled sides are reinforced to prevent sagging due to soil pressure.