Hi guys

I need to create a raised bed garden mostly to propagate plants. I have an area covered in sun for most of the day. I need to propagate some bushes and decorative grasses and this will also be an area where I keep the plants till I decide on their position and use in my backyard garden (long term project)
The area adjacent to the garage is paved with large and cheap rectangular slabs. The raised bed will look like below and I don't know if I can use plastic containers like below for my project. I need to do that because I will get all the soil for the two raised beds later. For now I need to move some grasses and small plants so I can build the layout of my garden. In time I will build the wooden frame for the raised bed and add more containers and soil so I can propagate the grasses

Is the below o good idea? Do you foresee any problems with this?