How to Plant a Container for a Rooftop or Balcony Garden

Now that you’ve blended your potting soil with one part topsoil, two parts sphagnum moss, and one part phosphorus, its time to prepare the pot. Remember, outdoor plants require plenty of drainage to stay healthy through summer’s rainfalls and humidity.
Step 1. Cover the drainage holes with curved pieces of broken dishware or pottery to permit drainage.
Step 2. Add a drainage layer. Styrofoam packing material is ideal since it’s lightweight, virtually indestructable, and easy to drain.
Step 3. Add a drainage barrier, such as a fiberglass screen, to keep the soil and drainage material from mixing.
Step 4. Add your soil, filling the container only three-quarters full and leaving room for the plant’s root ball.
Step 5. Add your plant, using loose soil to backfill any additional space around and above the root ball.
Step 6. Finally, add a half-inch layer of bark mulch.
Which revision is best to make the diagram more helpful?
an illustrated list of gardening tools
a text box describing the location of the garden
a caption indicating the purpose of the diagram
a label indicating the depth of the drainage layer