North facing balcony pot - help!

[StarsBrokenAgain]

I have a north facing concrete built in pot as part of my balcony that I would love to plant something in.

I'm in London (for climate info!) and would like something perennial with either interesting leaves or flowers, that can live in a fairly shallow long trough shaped pot. I can sort drainage I think, anyone got any suggestions?

Thanks in advance for the gardening wisdom!

Hydrangea petioloris. Wonder plant for north facing.

Or Hydrangea seemanii which is very similar but has advantage of being evergreen. Underplant with small spring flowering bulbs, and then summer bedding. You’ll need to be generous with food and watering though

Hostas. & Hellebores & Snowdrops in winter.

Snowdrops 😊

I have a caster oil plant in a big wooden planter which looks dramatic, and tolerates anything.