"Soil scientists have proven this time and time again. Putting coarse material, be it sand or stones, beneath potting soil will actually make the soil more likely to become waterlogged.
No more gravel in containers. Chalker-Scott recommends using good soil throughout the container and, of course, making sure the pot has drainage holes."
Yes I thought that might be up for disagreement. The thing is, I found it works. I’ve tried the all compost route and there’s been a higher rate of waterlogging. If you use a pot with lots of drainage holes it’s ok, but the majority use terracotta and ceramics with just the single small central drainage hole.
Well I think there are just so many variables as you say. Lab conditions rarely relate to real world. We’re all using different composts and different pots with different plants in different environments. Very hard to have one sweeping rule. I guess we can only do our best and find what works for us.
Not sure about the drainage question:
"Soil scientists have proven this time and time again. Putting coarse material, be it sand or stones, beneath potting soil will actually make the soil more likely to become waterlogged.
No more gravel in containers. Chalker-Scott recommends using good soil throughout the container and, of course, making sure the pot has drainage holes."
https://www.hortmag.com/container-gardening/myth-busting-gravel-containers#:~:text=has%20drainage%20holes.-,Dr.,no%20research%20behind%20this%20claim.
Yes I thought that might be up for disagreement. The thing is, I found it works. I’ve tried the all compost route and there’s been a higher rate of waterlogging. If you use a pot with lots of drainage holes it’s ok, but the majority use terracotta and ceramics with just the single small central drainage hole.
Hm - I discovered the truth of this when I had mass deaths. So there must be more variables. Horticulture is possibly under researched?
Well I think there are just so many variables as you say. Lab conditions rarely relate to real world. We’re all using different composts and different pots with different plants in different environments. Very hard to have one sweeping rule. I guess we can only do our best and find what works for us.