So you have back filled this ledge to bring it up to grade. Are you telling us you used all mulch to do this or there is soil under the mulch? What's to keep it from washing off the ledge in a heavy rain storm?
The final question is are you going to sink potted plants into the mulch for that planted look? If so careful consideration as to watering needs will need to be addressed, like how much and how often.

Dave

No back fill. Basically when we bought the house the back yard (mulched area)was filled with garbage tree's and trash, leaves, weeds.. and just plain gross. A year ago we chainsawed all the garbage tree's, had a stump grinder come and my husband cleaned the area. It looked like rock and a little dirt. My husband weed treated it with a sprayer and then covered the area with a barrier. We then had 12 yards of mulch dumped on it and then edged it. Basically Dave, its all rock. No room under there for any planting...unless i build it up. We have had numerous amounts of rain.. downright drenching... its been almost a whole year with rain and snow... I just wish there was not ledge.. then I could plant.