I build garden beds that are 27″ tall. Up till now I have recommended filling them 1/2 with sand or rock and black or potting
soil for the top half. My question is, would it be a problem if people used straw bales tipped on their sides? The stems would then run up and down for drainage. Black dirt or potting soil would be placed on top of the bales. I am quite sure this would work in the beginning, but I don't know if the straw would rot and stop or inhibit drainage.
Certified GKH Gardening Expert
It would work at first, but as it rots, there is no guarantee that it won't clog up. As long as there is plenty of compost or other means to aerate the soil, then some hay won't hurt. Some even plant directly into hay bales, but this can lead to infections quite quickly.