Raised Circular Keyhole Garden On a Slope

Hello fellow permies!
My family is moving in two weeks to a new home we just bought. Our garden bed is sloped gently. We’re interested in making circular keyhole raised garden beds. I was wondering if anyone has any experience or advice on constructing round raised keyhole beds on sloped land. Any ideas &/or advice are welcome!

I haven't done any keyhole gardens but a lot of raised beds on contour for directing runoff/catching rain water. I'm not sure what kind of climate you are in or what you wet seasons look like but on hills i'm pretty careful not to let too much water build up. I would make your keyhole small, and and your beds short if you get some pretty intense rainstorms sometimes, or make your keyhole more open and shallow, that way you aren't catching a pond, or at risk of blowing it out. also it's a good rule of thumb to stay twice the distance in height away from the edge of retaining walls like that, because that increases the load on them and the amount of water caught and sunk into the ground increases the hydrostatic pressure behind the wall. so if your raised bed is going to be 2ft tall, it should be placed at least 4 feet from the edge of the wall.

David F Paul wrote:I haven't done any keyhole gardens but a lot of raised beds on contour for directing runoff/catching rain water. I'm not sure what kind of climate you are in or what you wet seasons look like but on hills i'm pretty careful not to let too much water build up. I would make your keyhole small, and and your beds short if you get some pretty intense rainstorms sometimes, or make your keyhole more open and shallow, that way you aren't catching a pond, or at risk of blowing it out. also it's a good rule of thumb to stay twice the distance in height away from the edge of retaining walls like that, because that increases the load on them and the amount of water caught and sunk into the ground increases the hydrostatic pressure behind the wall. so if your raised bed is going to be 2ft tall, it should be placed at least 4 feet from the edge of the wall.

Thank you! That really brought attention to something I hadn’t considered: the retention wall! We’re really considering having a permaculture expert come out to guide us. We have a lot to learn and for some reason....I’m feeling time is short for us to get into proper gear considering the current climate.

David F Paul wrote:I haven't done any keyhole gardens but a lot of raised beds on contour for directing runoff/catching rain water. I'm not sure what kind of climate you are in or what you wet seasons look like but on hills i'm pretty careful not to let too much water build up. I would make your keyhole small, and and your beds short if you get some pretty intense rainstorms sometimes, or make your keyhole more open and shallow, that way you aren't catching a pond, or at risk of blowing it out. also it's a good rule of thumb to stay twice the distance in height away from the edge of retaining walls like that, because that increases the load on them and the amount of water caught and sunk into the ground increases the hydrostatic pressure behind the wall. so if your raised bed is going to be 2ft tall, it should be placed at least 4 feet from the edge of the wall.

Thank you! Our new home is in the foothills of the Sierra Nevadas in Central California. Rain season is the winter months.
Your response brought attention to something I hadn’t considered: the retention wall! We’re really considering having a permaculture expert come out to guide us if we can find someone in these parts. We have a lot to learn and for some reason....I’m feeling time is short for us to get into proper gear considering the current climate.

Sure! there are a lot of permaculture people out in california, so I'm sure that you will be able to find someone. best to get them out before you do anything too major that way they can set up the groundworks which is the most important/permanent part. Though a lot of folks (myself included) would recommend spending a year or so doing nothing but really observing the land in its current state, that is, if you aren't relying solely on farming for income and don't absolutely need to get started on stuff right away. It's sometimes hard to know what needs to be done without seeing everything in every season