Palm tree

Tree ferns are very beautiful if you can protect them from frost.They like shade & damp as well. I lost 2 in the "Beast from the East". They are shallow rooted.Also new Zealand Flax, Phormium, don't have a lot of root in proportion to their size.

Tree ferns don't have roots. You have to make sure that the trunk is well anchored.
Also you have to protect the crown from frost in the winter.
We have a small one in a pot. It goes outside in the summer, but comes I to the conservatory in the autumn.