Can anybody recommend a must have tree for a container

[T0mat0andch33s3]

Already have an Amalanchier, toying with a crab apple for all round year interest and benefits to wildlife but open to suggestions,

Flagpole cherry or other patio fruit trees - then you get fruit.

Acers also work well in large pots on a patio.

I believe fig trees do well in containers.

Buddleia, holly and hawthorn do well in pots and would be great for wildlife.

There are some lovely small buddleia varieties.

Acer

Yes Acers but in a sheltered spot.