I give props to anyone who tries to brighten up our city streets with a little horticulture. But seriously folks, no hort is better than bad hort:
What does it take to keep a few evergreens alive? A little water, 6 hours of sunlight/day, and decent drainage in the container, that's what. If that's more than you can manage, be a mensch and admit it. In horticulture (as in everything else) it's wise to know your limitations. I'm not saying you shouldn't try to learn and grow as a gardener, but when you abdicate responsibility for the plants in your care, we ALL suffer. On the other hand, a single tree underplanted with a few shade loving begonias make a lovely, simple corner planting.
Street plants put up with a lot more abuse than plants on rooftops and in window boxes. Not all New Yorkers appreciate horticulture and those that don't can be brutal. I wear gloves when working with street plants, and not just because of the dog pee. You find all sorts of things in tree pits and curbside gardens: used kleenex, half eaten food, prophylactics (that's right, you heard me). Believe it or not, people actually steal plants from street plantings; it's not unusual to find a gaping hole in your tree pit, where once there was a glorious Caladium. (Ask Other Ellen, she knows what I'm talking about.)
This time of year, lots of restaurants add outdoor cafes, often surrounded by planter boxes. Do you suppose there's a correlation between the care given to a planter on the sidewalk and the care given to the food in the kitchen? Where would you rather eat?
Perhaps I'll experiment. Except I'm NOT eating at the last place...that Hibiscus looks pathetic with no flowers and all its bare branch ends. It doesn't bode well for the food inside.