To fern or not to fern

hi all
I’m having two large planters built for the front of my cottage it has two walled areas either side of front door which face the road. The planters will sit in some shade (from the house and the walls) but will get the morning sun.
I’d like them to be low maintenance and evergreen, height isn’t and issue within reason...However I really fancy ferns and alliums..thoughts please ? Cheers/Diolch

 

Room for a young treefern?

 

Thanks for the suggestion..the boxes need to match..don’t want too many different things going on..slight ocd issue..

 

Welcome to Gardeners Corner Gaynor. We all garden in different areas of the country or for some of us further afield - so in turn different climates, and different plants that suit our area. It would be helpful if you placed your area in your avatar box please to give us a guide for your needs.