I am planning to build my first raised vegetable garden bed on my front yard.
However, since my septic drain field is located under that yard, I don't want
- The roots of my garden bed to potentially disrupt my installation
- The soil from my garden bed to get contaminated by the system
I was thinking of starting with a 4' x 6' bed of about 3 2"x6" planks high to grow basic vegetables (cherry tomatoes, cucumbers, carrots, bell peppers, maybe a few others), but am unsure how to prepare the bottom of the floor to isolate it from the soil beneath.
I guess I could also consider raising the bed from the floor entirely (maybe by having more smaller planter bins on posts).