The area containing the tables and chairs shall be separated from the pedestrian passageway by planters. The height of a planter shall not exceed 36 inches, as measured from the ground surface to the edge of the planter except at street corners where the height of a planter shall not exceed 30 inches as measured from the ground surface to the edge of the planter. The height of the plant material in the planter shall not exceed 18 inches, as measured from the top edge of the planter to the highest point of plant growth. Planters shall contain only approved plant material which shall consist of any of the following: Ilex, Juniper, Taxus (Yew); Geranium, Marigold, Begonia, Verbena, Ivy Geranium, Vinca Vince and Petunia. Soil mixture shall be 1/3 topsoil, 1/3 sand and 1/3 humus. Moisture gel shall be added to improve water holding capacity. Plant material shall be properly maintained and all plant material which dies or is damaged shall be replaced immediately. Planters which are damaged or in disrepair shall be replaced immediately. All planters shall be removed within five days of the expiration of an outdoor cafe license.