The following are exceptions to the provisions of this chapter:
1. Vegetable and/or flower gardens, purposefully planted, shall be permitted if they are maintained in compliance with this chapter.
2. Wood perennials, purposefully planted, shall be permitted if they are planted and maintained in compliance with this chapter, and Chapters 50 and 151 of this Code of Ordinances.
3. Prairie grass areas, wild flower planting areas, natural reserve and preserve areas, urban wood lots, wild life refuge and conservation areas, wetlands, and natural water way, all as recognized and identified by a governmental agency or a respected private conservation organization.