A 14'' planter was used with a depth of 6''. Examples of plants that can be used are:
There are all sorts of stones or pebbles that can be used. This is one example:)
2'' of gravel. You could grab a little bucket from a laneway or side of the road.
This is necessary to separate the soil from the gravel
The layer of soil doesn't need to be deep. Maybe 3'' in depth. If you get 2-3 cacti, you must put in a lot of sand because the drainage has to be excellent to prevent root rot or mildew.
Carefully de-pot each plant, especially sedums. Make sure the roots are completely covered by soil but don't tightly compact the soil down.
Add large rocks. Scrub each rock off, especially if you found it in the forest or it was in another pot. This prevents transferring bacteria or pests.
Add pebbles carefully around each plant.
Water maybe 1/4 Cup of water for each plant every 3 weeks during the summer. During winter months, water only every 2-3 months. BUT, your area may require more/less watering.
The most important thing to remember for a healthy planter is the amount of water. Over-watering will rot the roots and you'll see mold. Only water when the soil is completely dry. Happy planting!:)