| Last year, I dug a shallow trench between my plastic flowerbed edging and the lawn to reduce turf grass invasion and for appearance. I expected I would be able to drive my rider mower on the wall stones I used. Since I had used wall stones simply set into the soil around a small pond and they seem very solidly set, I assumed this would work well.
Unfortunately, the border stones sometimes tilt slightly as a mower wheel moves onto one edge of a stone and then the other. Naturally, I'm worried that one will tilt enough to contact a mower blade.
I don't want to set them in concrete, as I tend to gradually reduce the lawn area over the years. It seems to me that the edges of the stones don't have enough support. Obviously mere soil isn't doing the job. But I don't see why sand would do any better (it has been very dry here all Summer, so it's not that the soil is muddy).
So, I'm trying to figure out what material I can put between/under the stones to discourage them from moving. The local home project store suggested stone chips, and I've read that rough sand does provide some structural support, but I have been researching polymeric sand too.
I've read what I could find here and elsewhere about each, but most discussion is about patios or paths of close-fitting pavers that only have foot traffic.
So, if you were to build a stone border at lawn level that you could run a riding mower over and wanted to be able to pull it up in 3-5 years, what would you do?
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