Plants get heaved out by frost?? Do you use a lot of composted material? The reason I ask is because I have done that, and compost breaks down very quickly, which gives the appearance that the plants are heaving.... In regular soil, they should never move up, even after several years. Or, at least mine never have. With compost, they need to be topped off annually, and compost is airy, which allows roots to both freeze and dry out much easier. I also seriously doubt that you have more freeze thaw incidents than we have here. It can be brutal here.
At the moment, I have fewer than 200 named plants, and would like to get rid of all of them eventually.... except that I keep ordering more every year! I do have a few thousand seedlings though and have another batch of seeds stratifying now. My seeds are measured in "pounds".
