This is a general concept only. Part of making it successful would be adequate front-to-back depth of the planter. At the right side, I'm suggesting a rail between the post and house wall, if the planter doesn't extend that far. You might consider extending the planter back to the house and filling in that niche area between deck and bump-out and eliminating the need for the rail. If wide steps are flanked with cheekwalls their location will be obvious from a distance ... and they will look better. (I'm not suggesting the color red.)

rosiew Amazing - this post began more than a year ago and has life again. Thanks for your suggestion. The pergola is under construction now. We did give consideration to using greenhouse shade cloth but opted to install lattice atop. Should the shade be insufficient we'll make a change. Are afraid that the adjacent trees will cause leaves, etc. to be constantly on shade cloth and can blow away. Have had to downsize the shade area because the city said 12 x 16 is too large (now 8 x 12) - even though they previously approved the footings. The most incompetent, arrogant and disgusting lot of bureaucrats anywhere. No discussion, was told a variance would not be approved, just that everyone must follow the rules. If you ever have a week I'll expound on my true feelings!

It may cost less if the deck/patio wasn't there. As far as costs go, they are a regional thing and it is best to ask someone local, particularly those that may potentially be doing the work.

pictures needed