I just wanted to comment on the size and color of the planters. Kind of wondering if you are fighting a losing battle with black smallish ones. Few plants can tolerate having their roots that hot and dry. Particularly if the planters get the sun for much of the day. (although the planters are very pretty)
I don't like artificial plants but they may be warranted in this case. Put geraniums in the summer, mums in the fall, tulips in the spring. Fill with greenery and red berries in the winter.
They may be used by other people more than we realize. If they are kept seasonal, and moved around a bit occasionally, no one would know.
The only time they look tacky is when they are old, faded and out of season. Like having a bright pink bunch of flowers out in January, stuck along the sidewalk.
You would be saving yourself a lot of anxiety about that situation.