Oh - you mean stairs are for something else?
I have always liked crowding my entranceway with plants. Some wags say it is because I'm so lazy I don't want to carry the heavy pots too far out into the garden. (true)
Some say that it is because that's the only way I'll remember to water them when I see them wilting (true)
Some folks say it is because I can't see far enough away so I need plants beside my door to remind me that I'm a gardener. (true)
I however say that these are my guard plants.
These are the guardians of the sense of greenery of the place. They live year round with me and don't like to leave home for too far or too long. They remind me year round of summer and when the citrus go into bloom in the middle of a snowy January, I'm transported to a place of fragrance and magic.
The rest are old friends and you always like to keep old friends close.
There are some other fragrant plants there (night jessamine) and some herb pets that will go back into the house in the fall (rosemary, lemon verbena) along with the odd flowering or fragrant-leaf plant that is destined to raise my gardening soul in the dregs of January.
So for now, they get to live on the steps. They get their rightful place in my winter and summer life. And this is it for the summer.
I think I'm going to need bigger steps next year.