Owning a flower pot with water in it that isn’t capable of draining is considered a public nuisance.

Sec. 18-2. Weeds, trash, etc., as a public nuisance; removal by property owner or by city at owner’s expense; notice and hearing; lien for expenses. (a) The existence of weeds, trash, undergrowth, brush, filth, garbage or other refuse on any lot, tract or parcel of land within the city which has caused the property to…