Q.planting stonecrop perennials
How deep do I plant them? Also, the soil is mixed with river rock. Is that ok?
Your Stonecrop plants do not have a big root system and can be planted quite shallow in a well draining soil that rich in organic material.
Here are some articles that will help you get started!
There are many different types and varieties of Stonecrops and Sedums to enjoy and plant!