Trust me it works. You do not have anything to lose. Break a piece of your small trailing coleus and stick it in a pot of semps.
Do what the semps need. They are the focus because they are the permanent plant. If the coleus grows slow because of the lean soil and less water you will not have any problems. If the coleus loves the conditions and grows to fast you can clip the coleus or remove it from the pot. It is a annual. No loss.
You do not make perfect conditions for the coleus it is there as decor. Use it as decor that you use in your house move it if it does not work in the corner you place it but leave the couch.
