Finished the greenhouse project...

[BumRushDaShow]

22. Cool

Read about that a long time ago. The composting process does generate some heat and that stabilizes the temp at the root zone. Some even actually do vermicomposting in trenches like that - https://www.redwormcomposting.com/worm-composting/5-great-reasons-to-use-vermicomposting-trenches-pits/

And thanks for the link to that channel.

I container garden with shrubs and perennials and I know my "rule of thumb" is to select plants that are rated for at least 1, or better, 2 or more Zones colder than my own since the pots are sitting above ground and stay out year round. That would be plants from your USDA Zone (I am in 7a).