I have not seen this air pocket recommended in instructions for self-watering raised beds that use a media, such as gravel, to create the water reservoir. Instead, a material, such as landscaping fabric, is laid directly on the media to separate the reservoir from the potting medium. The potting medium is placed directly on the material. I am wondering how well plants grow without the air reaching the roots from the bottom. Does anyone have experience with this?

I know a self-watering raised bed can be made with an air pocket by suspending a platform above the water, as is done in a 5-gallon bucket, but I wondering about those without an air pocket. Are there problems that are unique to these, or can there be?

The gravel does not wick water. It's purpose is to hold up the soil (or potting mix) without wicking. Think of it this way: both the water reservoir, and the air gap above it just happen to be filled with gravel.

In any event, there should be an air pocket, in my opinion. I think the roots will rot otherwise. (unless you are growing rice or something).

McKenzie