I am trying to get rid of plastic (and bad paper). I started making wooden crates, but I still have to improve that. In the  meantime I use commercial crates that I get from the market (becomes harder every year, this is why i invest time in designing future boxes myself). I foud that one can use pure cellulose coffee filter (virgin cellulose garanteed in eko butik here) and shape them with the wooden tool i got in sweden. They degrade in a month but are good enough to shape a stable root system that can be separated with hands. Filters with plants and compost are placed in a  wooden crates that can be moved around.