As I began cleaning my raised beds this spring I noticed that the stacked stones are loose and soil is leaking from the beds. Does anyone know how to stabilize the beds without removing the stones?
The beds are about 30 inches tall, approximately 30 feet long, 5 to 6 feet deep. They are on a sloped yard and are level with the upper level of the yard. There are currently only yucca plants and assorted perennials in the beds although if I can halt the movement of the stones in the beds I will plant evergreen shrubs and deciduous shrubs in the beds.
During the construction of the wall, a landscape mesh would have been ideal to put behind the rocks. Obviously, that advice is not very helpful at this point. You can try taking pieces of mesh and try to tuck it in behind as many rocks as you can. This eliminates the small particles of soil from seeping through. Another option is to add concrete between the stones. Mix concrete and place into a bag, twist off the top, snip off a corner, and squeeze into cracks (a chef's pastry bag is essentially what you are making) and tool with a stick or tuckpoint trowel. As it begins to harden, you can take a small wisk broom or similar device and brush it away from the rocks if you slopped more on than you wanted and clean up the area. If you don't necessarily want to see all that concrete, you can squish smaller rocks in those areas to conceal it, and also add strength acting as shims. You are turning a dry stacked rock wall into a mortared wall, and it should hold up. Be aware though, the more weight you add on top of the bed could eventually be more than the wall can bear if you are not able to stablize it at this point. However, a strong wall will benefit from a rooted bed. Good luck!