Looking for plant recommendation for outside pot

Looking for recommendation for replacement plant

Pot in photo is 18" diameter x 18" high and buxus about ten years old and not healthy.

Looking to replace it with either another topiary plant or something else.

Needs to be low maintenance and ideally stay out all year in south wales

 

Hello, welcome to GC You don't say whether the pot is in sun or shade, but here are a few ideas for either: Euonymous fortunei, Hebe, Nandina domestica 'Firepower', dwarf Pittosporum tobira, Convolvulus cneorum, dwarf Photinia, Hedera 'Glacier' trained on a frame, HTH!