Q.How can I promote drainage from my raised garden bed. The natural soil underneath the bed is a hard clay type. I am concerned that
water will not transfer from the bed to the ground underneath. The bed is built on a somewhat steep bank. I plan on adding more beds in a terrace style.
Certified GKH Gardening Expert
I would say that your best bet would be to lift those beds and dig a pit the size of the bed, but only 3 or 4 inches deep. Fill this with gravel, then place your raised bed that has landscaping fabric over the bottom on top of the rocks and that will allow drainage.
You could also opt to drill holes along the bottom inch or two of the raised bed. This may not be the best option, but it can offer some relief in a pinch.
This article will help you with raised bed gardening: https://www.gardeningknowhow.com/edible/vegetables/vgen/raised-vegetable-gardens.htm